MyMedR

Displaying publications 1 - 20 of 47 in total

Abstract:

Sort:

New One-Pot Synthesis of 1,3,5-Triazines: Three-Component Condensation, Dimroth Rearrangement, and Dehydrogenative Aromatization

Junaid A, Lim FPL, Tiekink ERT, Dolzhenko AV

ACS Comb Sci, 2019 07 08;21(7):548-555.
PMID: 31180634 DOI: 10.1021/acscombsci.9b00079

A new, effective one-pot synthesis of the 6, N2-diaryl-1,3,5-triazine-2,4-diamines under microwave irradiation was developed. The method involved an initial three-component condensation of cyanoguanidine, aromatic aldehydes, and arylamines in the presence of hydrochloric acid. Without isolation, the resulting 1,6-diaryl-1,6-dihydro-1,3,5-triazine-2,4-diamines were treated with a base to initiate Dimroth rearrangement and spontaneous dehydrogenative aromatization, affording the desired compounds. The developed method was found to be sufficiently general in scope, tolerating various aromatic aldehydes and amines; by using their combinations in the first step, a representative library of 110 compounds was successfully prepared and screened for anticancer properties.

Matched MeSH terms: Hydrochloric Acid/pharmacology*; Hydrochloric Acid/chemistry
Fulltext Evaluation of closed vessel microwave digestion of fish muscle with various solvent combinations using fractional factorial design

Low, K.H., Zain, S.M., Abas, M.R., Ali Mohd, M.

ASM Science Journal, 2009;3(1):71-76.
MyJurnal

Fractional factorial design was utilized to evaluate the effect of combinations of nitric acid, hydrogen peroxide, hydrochloric acid and water for microwave digestion of fish muscle. Upon digestion, copper, iron and zinc were determined by flame atomic absorption spectroscopy. H2O2 and HCl volumes were found to be the most significant parameters which resulted in good metal recoveries. This is especially so for the effect of HCl on Fe recovery. The results indicated that the combination of 4 mL 65% HNO3, 2 mL 30% H2O2 and 2 mL 30% HCl gave the most satisfactory percentage recovery. There was good agreement between measured and certified values for all metals with respect to the DORM-3 fish protein.

Matched MeSH terms: Hydrochloric Acid
Fulltext Purification of metallurgical grade silicon by acid leaching

Lashgari, V.A., Yoozbashizadeh, H.

ASM Science Journal, 2007;1(1):37-41.
MyJurnal

Silicon, as the most important electronic material, has a lot of applications in the electronic industry and this includes the use of silicon in solar cells. One of the solar grade silicon production processes is the use of acid leaching for the removal of metallic impurities from silicon. The main advantage of this process for silicon purification is that it is based on a low temperature process. The purification of metallurgical grade silicon by acid leaching was studied as a function of time, temperature and etching. Based upon experimental results and under optimum conditions, it was possible to remove 41%, 71% and 25% of iron, calcium and aluminum respectively, with the use of aqua regia.

Matched MeSH terms: Hydrochloric Acid
Fulltext Ime course detachment of biofilms in pipes by hydrochlorination

Shanzay, A., Siddra, T. A., Warda, F., Sheeza, A., Maryam, A., Aina, S. Z., et al.

Asian Journal of Medicine and Biomedicine, 2018;1(1):28-31.
MyJurnal

Bacterial biofilms are a complex community of microbes in which the cells are embedded in a polysaccharide matrix.
This slime is a mean of protection in hostile environments. Biofilms in hospital settings are perilous as they not only
make treatment difficult, cause blockage of pipes but are also cause of serious nosocomial infections thus making their
dispersal an even more important phenomenon. Any foaming method is not applicable at all places for the cleaning of
biofilms hence biofilm dispersal by household sweep containing hydrochloric acid was checked using the microliter
plate assay as dispersal strategy. Bacteria from hospital waste disposal pipes were isolated, its ability to form biofilm
was noted under different time intervals and then finally biofilm degradation was done using different concentrations
of household sweep. It was noted that household sweep can be successfully employed at many places especially waste
disposal pipes and acid resistant tubes. Our results indicated that 20% sweep (HCl conc. 1%) if used for only one
minute can reduce the biofilms to 50%. Similarly increasing contact time can reduce the biofilms further.

Matched MeSH terms: Hydrochloric Acid
Fulltext Enhanced blood compatibility of metallocene polyethylene subjected to hydrochloric acid treatment for cardiovascular implants

Jaganathan SK, Mohandas H, Sivakumar G, Kasi P, Sudheer T, Avineri Veetil S, et al.

Biomed Res Int, 2014;2014:963149.
PMID: 24955370 DOI: 10.1155/2014/963149

Blood compatibility of metallocene polyethylene (mPE) was investigated after modifying the surface using hydrochloric acid. Contact angle of the mPE exposed to HCl poses a decrease in its value which indicates increasing wettability and better blood compatibility. Surface of mPE analyzed by using FTIR revealed no significant changes in its functional groups after treatment. Furthermore, scanning electron microscope images supported the increasing wettability through the modifications like pit formations and etching on the acid rendered surface. To evaluate the effect of acid treatment on the coagulation cascade, prothrombin time (PT) and activated partial thromboplastin time (APTT) were measured. Both PT and APTT were delayed significantly (P < 0.05) after 60 min exposure implying improved blood compatibility of the surfaces. Hemolysis assay of the treated surface showed a remarkable decrease in the percentage of lysis of red blood cells when compared with untreated surface. Moreover, platelet adhesion assay demonstrated that HCl exposed surfaces deter the attachment of platelets and thereby reduce the chances of activation of blood coagulation cascade. These results confirmed the enhanced blood compatibility of mPE after HCl exposure which can be utilized for cardiovascular implants like artificial vascular prostheses, implants, and various blood contacting devices.

Matched MeSH terms: Hydrochloric Acid/chemistry
Bone regeneration performance of surface-treated porous titanium

Amin Yavari S, van der Stok J, Chai YC, Wauthle R, Tahmasebi Birgani Z, Habibovic P, et al.

Biomaterials, 2014 Aug;35(24):6172-81.
PMID: 24811260 DOI: 10.1016/j.biomaterials.2014.04.054

The large surface area of highly porous titanium structures produced by additive manufacturing can be modified using biofunctionalizing surface treatments to improve the bone regeneration performance of these otherwise bioinert biomaterials. In this longitudinal study, we applied and compared three types of biofunctionalizing surface treatments, namely acid-alkali (AcAl), alkali-acid-heat treatment (AlAcH), and anodizing-heat treatment (AnH). The effects of treatments on apatite forming ability, cell attachment, cell proliferation, osteogenic gene expression, bone regeneration, biomechanical stability, and bone-biomaterial contact were evaluated using apatite forming ability test, cell culture assays, and animal experiments. It was found that AcAl and AnH work through completely different routes. While AcAl improved the apatite forming ability of as-manufactured (AsM) specimens, it did not have any positive effect on cell attachment, cell proliferation, and osteogenic gene expression. In contrast, AnH did not improve the apatite forming ability of AsM specimens but showed significantly better cell attachment, cell proliferation, and expression of osteogenic markers. The performance of AlAcH in terms of apatite forming ability and cell response was in between both extremes of AnH and AsM. AcAl resulted in significantly larger volumes of newly formed bone within the pores of the scaffold as compared to AnH. Interestingly, larger volumes of regenerated bone did not translate into improved biomechanical stability as AnH exhibited significantly better biomechanical stability as compared to AcAl suggesting that the beneficial effects of cell-nanotopography modulations somehow surpassed the benefits of improved apatite forming ability. In conclusion, the applied surface treatments have considerable effects on apatite forming ability, cell attachment, cell proliferation, and bone ingrowth of the studied biomaterials. The relationship between these properties and the bone-implant biomechanics is, however, not trivial.

Matched MeSH terms: Hydrochloric Acid/pharmacology
Fulltext A visual tutorial on the synthesis of gold nanoparticles

Low A, Bansal V

Biomed Imaging Interv J, 2010 01 01;6(1):e9.
PMID: 21611068 DOI: 10.2349/biij.6.1.e9

Many papers have been written on the synthesis of gold nanoparticles but very few included pictures of the process, and none of them used video to show the whole process of synthesis. This paper records the process of synthesis of gold nanoparticles using video clips. Every process from cleaning of glassware, an important step in the synthesis of metallic nanoparticles, to the dialysis process is shown. It also includes the preparation of aqua regia and the actual synthesis of gold nanoparticles. In some papers, the dialysis process was omitted, but in this paper, it is included to complete the whole process as it is being used for purification.

Matched MeSH terms: Hydrochloric Acid
Optimization of cell disruption methods for efficient recovery of bioactive metabolites via NMR of three freshwater microalgae (chlorophyta)

Ma NL, Teh KY, Lam SS, Kaben AM, Cha TS

Bioresour Technol, 2015 Aug;190:536-42.
PMID: 25812996 DOI: 10.1016/j.biortech.2015.03.036

This study demonstrates the use of NMR techniques coupled with chemometric analysis as a high throughput data mining method to identify and examine the efficiency of different disruption techniques tested on microalgae (Chlorella variabilis, Scenedesmus regularis and Ankistrodesmus gracilis). The yield and chemical diversity from the disruptions together with the effects of pre-oven and pre-freeze drying prior to disruption techniques were discussed. HCl extraction showed the highest recovery of oil compounds from the disrupted microalgae (up to 90%). In contrast, NMR analysis showed the highest intensity of bioactive metabolites obtained for homogenized extracts pre-treated with freeze-drying, indicating that homogenizing is a more favorable approach to recover bioactive substances from the disrupted microalgae. The results show the potential of NMR as a useful metabolic fingerprinting tool for assessing compound diversity in complex microalgae extracts.

Matched MeSH terms: Hydrochloric Acid/chemistry*
Multistage optimizations of slow pyrolysis synthesis of biochar from palm oil sludge for adsorption of lead

Lee XJ, Lee LY, Hiew BYZ, Gan S, Thangalazhy-Gopakumar S, Kiat Ng H

Bioresour Technol, 2017 Dec;245(Pt A):944-953.
PMID: 28946195 DOI: 10.1016/j.biortech.2017.08.175

This research investigated the removal of lead (Pb(2+)) by a novel biochar derived from palm oil sludge (POS-char) by slow pyrolysis. Multistage optimizations with central composite design were carried out to firstly optimize pyrolysis parameters to produce the best POS-char for Pb(2+) removal and secondly to optimize adsorption conditions for the highest removal of Pb(2+). The optimum pyrolysis parameters were nitrogen flowrateof30mLmin(-1), heating rateof10°Cmin(-1), temperatureof500°C and timeof30min. The optimum Pb(2+) adsorption conditions were concentrationof200mgL(-1), timeof60min, dosageof0.3g and pH of 3.02. The various functional groups within POS-char played a vital role in Pb(2+) uptake. Regeneration was demonstrated to be feasible using hydrochloric acid. Adsorption equilibrium was best described by Freundlich model. At low concentration range, adsorption kinetic obeyed pseudo-first-order model, but at high concentration range, it followed pseudo-second-order model. Overall, the results highlighted that POS-char is an effective adsorbent for Pb(2+) removal.

Matched MeSH terms: Hydrochloric Acid
Relative bioavailability of the hydrochloride, sulphate and ethyl carbonate salts of quinine

Jamaludin A, Mohamad M, Navaratnam V, Selliah K, Tan SC, Wernsdorfer WH, et al.

Br J Clin Pharmacol, 1988 Feb;25(2):261-3.
PMID: 3358888

The hydrochloride, sulphate and ethylcarbonate salts of quinine were given in single oral doses (600 mg base equivalent) to nine healthy male subjects according to a cross-over design. No statistically significant differences were noted in the plasma drug concentration-time profiles although inter- and intra-subject variation in AUC, Cmax and tmax values was appreciable. The ethylcarbonate salt may be preferred for use in paediatric patients because of its neutral taste.

Matched MeSH terms: Hydrochloric Acid
Verifying measurements of residual calcium content in demineralised cortical bone

Ariffin AF, Yusof N, Mohd S, Rahman SA, Ramalingam S, Mansor A, et al.

Cell Tissue Bank, 2019 Dec;20(4):527-534.
PMID: 31456097 DOI: 10.1007/s10561-019-09785-4

Calcium contents of demineralised human cortical bone determined by titrimetric assay and atomic absorption spectrophotometry technique were verified by comparing to neutron activation analysis which has high recovery of more than 90%. Conversion factors determined from the comparison is necessary to correct the calcium content for each technique. Femurs from cadaveric donors were cut into cortical rings and demineralised in 0.5 M hydrochloric acid for varying immersion times. Initial calcium content in the cortical bone measured by titration was 4.57%, only 21% of the measurement by neutron activation analysis; while measured by atomic absorption spectrophotometer was 13.4%, only 61% of neutron activation analysis. By comparing more readings with the measurements by neutron activation analysis with 93% recovery, a conversion factor of 4.83 was verified and applied for the readings by titration and 1.45 for atomic absorption spectrophotometer in calculating the correct calcium contents. The residual calcium content started to reduce after the cortical bone was demineralised in hydrochloric acid for 8 h and reduced to 13% after 24 h. Using the linear relationship, the residual calcium content could be reduced to less than 8% after immersion in hydrochloric acid for 40 h. Atomic absorption spectrophotometry technique is the method of choice for calcium content determination as it is more reliable compared to titrimetric assay.

Matched MeSH terms: Hydrochloric Acid/chemistry
Anti-Ulcerogenic and Cytoprotective Effects of Saharian (Sidr) Honey from Algeria

Djebli N, Mustafa MR, Keskin M, Kolayli S

Comb Chem High Throughput Screen, 2021;24(10):1664-1670.
PMID: 33208062 DOI: 10.2174/1386207323999201117114008

AIM AND OBJECTIVE: This study aimed at investigating the gastro-protective effects of Algerian Sahara (Sidr) honey from Apis mellifera intermissa against HCl/Ethanol-induced gastric ulcers in rats.
MATERIALS AND METHODS: Total phenolic content, antioxidant activity and phenolic compounds were determined. Then, three groups of rats (control, HCl/ Ethanol-induced ulcer, and orally administered honey) were used for the determination of gastro-protective effect of Sidr honey.
RESULTS: Total phenolic content, total flavonoid content, and DPPH activity of the honey sample were determined as 47.35±3.35 mg GAE/ 100 g, 2.13±0.17 mg QE/ 100 g, and 229.24±0.02 mg/mL, respectively. Oral pretreatment of rats with honey (1.2 g/Kg body weight orally at an interval of 2 days) protected gastric mucosa against HCl/Ethanol-induced damage by decreasing ulcer score, the volume and acidity of gastric juice and increasing pH.
CONCLUSION: These results were confirmed by the histological assessment, which demonstrated a significant gastro-protective activity of Saharian (Sidr) honey against HCl/Ethanol-induced stomach ulcer. Plasma tumor necrosis factor-α, IL-6 and PGE2 were also measured. Sahara honey significantly decreased the plasma TNF-α, PGE2, and IL-6 concentrations.

Matched MeSH terms: Hydrochloric Acid
Non-erosive reflux disease (NERD), symptomatic and asymptomatic erosive reflux disease (ERD): from hypersensitive to hyposensitive esophagus

Hartono JL, Qua CS, Goh KL

Dig Dis Sci, 2011 Jan;56(1):90-6.
PMID: 20467897 DOI: 10.1007/s10620-010-1275-5

AIMS: To compare the esophageal sensitivity to acid and saline in patients with symptomatic and asymptomatic erosive reflux disease (ERD), non-erosive reflux disease (NERD) and controls, and to assess the response to proton-pump inhibitors in patients with symptomatic ERD and NERD.
METHODOLOGY: Patients with GERD and a control group of healthy asymptomatic volunteers were recruited. All subjects underwent esophagogastroduodenoscopy and the acid-saline perfusion test. Symptomatic ERD and NERD patients were given rabeprazole 20 mg twice daily for 2 weeks and their response to treatment assessed.
RESULTS: A total of 105 subjects were recruited: ERD=37 (symptomatic=24, asymptomatic=13), NERD=34 and controls=34. During saline perfusion, only the NERD group recorded a significantly higher sensitivity score compared to controls (2.74±7.28 vs. 0) (p=0.035). During acid perfusion, symptomatic ERD (15.42±13.42) and NERD (16.71±15.04) had significantly higher scores versus controls and asymptomatic ERD patients (both p<0.001). The mean %∆ reflux symptom score following treatment was significantly higher in symptomatic ERD patients compared to NERD patients (89.08±21.67 vs. 58.53±32.54; p<0.001).
CONCLUSIONS: Patients with NERD were a generally hypersensitive group while asymptomatic ERD patients represent a hyposensitive group of patients which merits further study.

Matched MeSH terms: Hydrochloric Acid/adverse effects
Insights into the equilibrium, kinetic and thermodynamics of nickel removal by environmental friendly Lansium domesticum peel biosorbent

Lam YF, Lee LY, Chua SJ, Lim SS, Gan S

Ecotoxicol Environ Saf, 2016 May;127:61-70.
PMID: 26802563 DOI: 10.1016/j.ecoenv.2016.01.003

Lansium domesticum peel (LDP), a waste material generated from the fruit consumption, was evaluated as a biosorbent for nickel removal from aqueous media. The effects of dosage, contact time, initial pH, initial concentration and temperature on the biosorption process were investigated in batch experiments. Equilibrium data were fitted by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models using nonlinear regression method with the best-fit model evaluated based on coefficient of determination (R(2)) and Chi-square (χ(2)). The best-fit isotherm was found to be the Langmuir model exhibiting R(2) very close to unity (0.997-0.999), smallest χ(2) (0.0138-0.0562) and largest biosorption capacity (10.1mg/g) at 30°C. Kinetic studies showed that the initial nickel removal was rapid with the equilibrium state established within 30min. Pseudo-second-order model was the best-fit kinetic model indicating the chemisorption nature of the biosorption process. Further data analysis by the intraparticle diffusion model revealed the involvement of several rate-controlling steps such as boundary layer and intraparticle diffusion. Thermodynamically, the process was exothermic, spontaneous and feasible. Regeneration studies indicated that LDP biosorbent could be regenerated using hydrochloric acid solution with up to 85% efficiency. The present investigation proved that LDP having no economic value can be used as an alternative eco-friendly biosorbent for remediation of nickel contaminated water.

Matched MeSH terms: Hydrochloric Acid
Utilization of red mud waste into mesoporous ZSM-5 for methylene blue adsorption-desorption studies

Tehubijuluw H, Subagyo R, Yulita MF, Nugraha RE, Kusumawati Y, Bahruji H, et al.

Environ Sci Pollut Res Int, 2021 Mar 13.
PMID: 33712959 DOI: 10.1007/s11356-021-13285-y

Red mud as industrial waste from bauxite was utilized as a precursor for the synthesis of mesoporous ZSM-5. A high concentration of iron oxide in red mud was successfully removed using alkali fusion treatment. Mesoporous ZSM-5 was synthesized using cetyltrimethylammonium bromide (CTABr) as a template via dual-hydrothermal method, and the effect of crystallization time was investigated towards the formation of mesopores. Characterization using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption-desorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) indicated the formation of cubic crystallite ZSM-5 with high surface area and mesopore volume within 6 h of crystallization. Increasing the crystallization time revealed the evolution of highly crystalline ZSM-5; however, the surface area and mesoporosity were significantly reduced. The effect of mesoporosity was investigated on the adsorption of methylene blue (MB). Kinetic and thermodynamic analysis of MB adsorption on mesoporous ZSM-5 was carried out at a variation of adsorption parameters such as the concentration of MB solution, the temperatures of solution, and the amount of adsorbent. Finally, methanol, 1-butanol, acetone, hydrochloric acid (HCl), and acetonitrile were used as desorbing agents to investigate the reusability and stability of mesoporous ZSM-5 as an adsorbent for MB removal.

Matched MeSH terms: Hydrochloric Acid
Fulltext Essential Oils Derived from Momordica charantia Seeds Exhibited Antiulcer Activity against Hydrogen Chloride/Ethanol and Indomethacin

Abu Bakar N', Hakim Abdullah MN, Lim V, Yong YK

Evid Based Complement Alternat Med, 2021;2021:5525584.
PMID: 33976701 DOI: 10.1155/2021/5525584

Momordica charantia (MC) is popular for its medicinal uses especially for treating diabetic-related complications. However, the antiulcer activity of essential oil derived from the seeds has not been systematically studied. This study aims to evaluate the gastroprotective activities of essential oil derived from the seed of MC induced by hydrochloride acid/ethanol (HCl/EtOH) and indomethacin and pylorus-ligation model. Gastric ulceration was induced by oral administration of HCl/EtOH solution or indomethacin on day 7 after animals have been pretreated with testing compounds. The first group received just distilled water and the second group received ranitidine (100 mg/kg). Groups 3, 4, and 5 received 10, 50, and 100 mg/kg of essential oil based on their body weight (10 mL/kg), respectively. Macroscopically, pretreatment of essential oil extracted from MC significantly decreased ulceration induced by HCl/EtOH and indomethacin in vivo. Microscopically, essential oil also significantly suppressed the formation of edema, epithelial disruption, and mucosa erosions. Moreover, essential oil significantly elevated the pH without decreasing the total acidity of the gastric juice and was able to increase the amount of adherent mucus compared to control. Current results provide scientific basis to the ethno-pharmacological usage of the MC in preventing ulcer formation induced by HCl/EtOH and indomethacin.

Matched MeSH terms: Hydrochloric Acid
Recovering obliterated engraved marks on aluminium surfaces by etching technique

Baharum MI, Kuppuswamy R, Rahman AA

Forensic Sci Int, 2008 May 20;177(2-3):221-7.
PMID: 18313246 DOI: 10.1016/j.forsciint.2008.01.004

A study has been made of the characteristics of restoration of obliterated engraved marks on aluminium surfaces by etching technique. By etching different reagents on 0.61mm thick sheets of aluminium (99wt%) on which some engraved marks had been erased to different depths it was found that the reagent 60% hydrochloric acid and 40% sodium hydroxide on alternate swabbing on the surfaces was found to be the most sensitive one for these metal surfaces. This reagent was able to restore marks in the above plates erased down to 0.04mm below the bottom of the engraving. The marks also presented excellent contrast with the background. This reagent was further experimented with similar aluminium surfaces, but of relatively greater thickness of 1.5mm. It was noticed that the recovery depth increased slightly to 0.06mm; this suggested the dependence of recovery depth on the thickness of the sheet metal. Further, the depth of restoration decreased in cases where the original number was erased and over which a new number was engraved; the latter results are similar to those of steel surfaces reported earlier [M.A.M. Zaili, R. Kuppuswamy, H. Harun, Restoration of engraved marks on steel surfaces by etching technique, Forensic Sci. Int. 171 (2007) 27-32].

Matched MeSH terms: Hydrochloric Acid
On the sensitivity of some common metallographic reagents to restoring obliterated marks on medium carbon (0.31% C) steel surfaces

Yin SH, Kuppuswamy R

Forensic Sci Int, 2009 Jan 10;183(1-3):50-3.
PMID: 19041202 DOI: 10.1016/j.forsciint.2008.10.009

Chemical etching, which is the most sensitive method to recover obliterated serial numbers on metal surfaces, has been practised quite successfully in forensic science laboratories all over the world. A large number of etchants suitable for particular metal surfaces based on empirical studies is available in the literature. This article reviews the sensitivity and efficacy of some popular etchants for recovering obliterated marks on medium carbon steel (0.31% C with ferrite-pearlite microstructure) used in automobile parts. The experiments involved engraving these carbon steel plates with some alphanumeric characters using a computer controlled machine "Gravograph" and erasing them to several depths below the bottom of their engraving depth. Seven metallographic reagents of which most of them were copper containing compounds were chosen for etching. The erased plates were etched with every one of these etchants using swabbing method. The results have revealed that Fry's reagent comprising cupric chloride 90 g, hydrochloric acid 120 mL and water 100mL provided the necessary contrast and was concluded to be the most sensitive. The same reagent was recommended by earlier workers for revealing strain lines in steel surfaces. Earlier, another reagent containing 5 g copper sulphate, 60 mL water, 30 mL (conc.) ammonium hydroxide, and 60 mL (conc.) hydrochloric acid was proved to be more sensitive to restore erased marks on low carbon steel (0.1% C with ferrite-pearlite structure) [M.A.M. Zaili, R. Kuppuswamy, H. Harun, Restoration of engraved marks on steel surfaces by etching technique, Forensic Sci. Int. 171 (2007) 27-32]. Thus the sensitivity of the etching reagent on steel surfaces appeared to be dependent on the content of carbon in the steel.

Matched MeSH terms: Hydrochloric Acid
Restoration of engraved marks on steel surfaces by etching technique

Zaili MA, Kuppuswamy R, Harun H

Forensic Sci Int, 2007 Aug 24;171(1):27-32.
PMID: 17088038

It is known that restoration of erased engraved identification marks on the engine and the chassis of a car or on a firearm has low success rate. Unlike stamping, engraving on a metal surface leaves no pronounced, permanent subsurface deformation in the crystalline structure, also called dislocation that can be revealed by suitable methods. Hence, the current research work investigated whether metallographic reagents used in the restoration of stamp (compression) marks could be applied to recover engraved marks on steel surfaces and also to establish the sensitivity and effectiveness of some of these reagents for the restoration of the marks. Experiments were conducted by mechanically engraving alphanumeric characters on several steel plates using a computer controlled engraving machine called Gravograph. The markings were later erased from the above steel plates by removing the metal in stages of 0.01 mm through 0.04 mm below the bottom of the engraving. Several plates were thus prepared wherein each one had been abraded to a specific depth. Then eight metallographic reagents were tested on each one of the above erased plates using a swabbing technique. The results had shown that while most of the reagents were able to restore marks up to certain levels of erasure, the reagent 5 g copper sulphate, 60 ml water, 30 ml concentrated ammonium hydroxide and 60 ml concentrated hydrochloric acid restored marks erased to a depth of 0.04 mm below the engraving depth, thus presenting itself the most sensitive reagent. Quite significantly, the above reagent was also able to decipher successfully the original engraved marks that had been erased and engraved with a new number, or obliterated by centre punching. The results of this research work should benefit the forensic practitioners engaged in the serial number recovery on vehicles, firearms and other objects.

Matched MeSH terms: Hydrochloric Acid
Fulltext Comparative chemical characteristics of hydrochloric acid- and ammonium oxalate-extracted pectin from roselle (Hibiscus sabdariffa L.) calyces

Nazaruddin, R., Noor Baiti, A.A., Foo, S.C., Tan, Y.N., Ayob, M.K.

International Food Research Journal, 2013;20(1):281-284.
MyJurnal

Recent research suggesting the existence of potential source of pectin from roselle calyces. Pectin was successfully extracted from seven different varieties of roselle calyces. Pectin extraction was conducted using hydrochloric acid (HCl, 0.03 N, pH 1.5) or ammonium oxalate (0.25% w/v, pH 4.6) at 85⁰C for 1 h. Chemical characteristics of the HCl- and ammonium oxalate extracted pectin were compared. Results indicated that ammonium oxalate exhibited greater efficiency in pectin extraction than HCl. Highest pectin yield at 18.7% was obtained by ammonium oxalate extraction of roselle calyx variety Acc.6 compared to only 9.77% by HCl extraction. The lowest pectin yield at 11.3% and 5.78% were observed respectively in ammonium oxalate and HCl extractions of roselle calyx variety UKMR-3. Some important characteristics of ammonium oxalate extracted pectin of roselle Acc.6 were 5.98% moisture, 3.81% ash, 4.64% methoxyl content, 42.24% anhydrouronic acid (AUA) and degree of esterification (DE) 60%. This study suggested that the high DE% roselle pectin is an alternative source of pectin for food industry.

Matched MeSH terms: Hydrochloric Acid

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links