Kobalt sulfida telah dihasilkan dengan kaedah pemendakan kimia di dalam kehadiran 0.1% ester sukrosa S1670s. Corak pembelauan sinar-x (XRD) menunjukkan kobalt sulfida yang dihasilkan mempunyai sifat amofos dan analisis sinar-x (EDX) menunjukkan kobalt sulfida yang terbentuk mempunyai nisbah atom Co: S dalam 1:1.08 iaitu CoS. CoS yang terbentuk mempunyai struktur liang bersaiz nano (~10 nm) apabila diperhatikan di bawah elektron mikroskop transmisi (TEM) dan disahkan oleh ujian penjerapan gas nitrogen (BET). Pembentukan struktur liang adalah disebabkan oleh struktur misel ester sukrosa yang mempunyai saiz misel dalam lingkungan 10 nm. CoS yang dihasilkan diuji keupayaan penjerapan dengan metilena biru sebagai sampel pewarna. Didapati keupayaan penjerapan optimum CoS ialah 110 mg/g dan pH yang paling sesuai untuk penjerapan berlaku adalah lebih daripada 6.
Penyingkiran boron dalam larutan akuas secara penjerapan telah dikaji dengan menggunakan penjerap komposit yang menggabungkan zeolit, batu kapur, karbon teraktif dan buangan arang sekam padi. Parameter optimum seperti pH, masa sentuhan optimum dan dos bahan penjerap dikaji. Kajian isoterma penjerapan dan kinetik penjerapan turut dijalankan. Hasil penyelidikan menunjukkan penyingkiran boron paling optimum berlaku pada pH5 dan masa sentuhan optimum ialah pada minit ke 120. Dos optimum bagi penyingkiran boron dalam larutan akuas ialah pada dos 280 g/L dan penyingkiran yang dapat dilakukan ialah sebanyak 50.49%. Dalam kajian isoterma, model isoterma Langmuir dan Freundlich telah diaplikasikan dan hasil kajian membuktikan bahawa kajian isoterma penjerapan adalah mematuhi model isoterma Langmuir (R2 = 0.8792). Nilai kapasiti penjerapan maksimum (qm) yang diperoleh daripada model isoterma Langmuir adalah 1.8985 mg/g. Kajian kinetik penjerapan dijalankan untuk mengetahui mekanisme proses penjerapan dan hasil kajian menunjukkan kadar kinetik bagi penjerapan boron ini adalah mematuhi model kinetik tertib kedua. Pekali korelasi yang diperoleh untuk model kinetik tertib kedua ini adalah 0.9929. Ini mencadangkan bahawa kinetik penjerapan boron adalah dipengaruhi oleh proses kimia.
Hidrogen merupakan sumber tenaga yang boleh diperbaharui dan efektif. Hidrogen boleh dihasilkan melalui fotofermentasi oleh bakteria ungu tanpa sulfur seperti Rhodobacter sphaeroides disebabkan kebolehan yang tinggi dalam menghasilkan hidrogen dalam keadaan anaerobik. Dalam kajian ini, bakteria dieram di dalam botol serum 100 mL dalam keadaan anaerobik. Kajian ini bertujuan untuk memaksimumkan penghasilan hidrogen oleh Rhodobacter sphaeroides NCIMB 8253 yang melibatkan kajian mengenai inokulum dalam keadaan aerobik dan anaerobik, kesan pH awal dan kesan keamatan cahaya terhadap penghasilan hidrogen. Daripada uji kaji yang dilakukan, didapati bahawa inokulum yang dieram pada keadaan anaerobik menghasilkan hidrogen tertinggi iaitu 220.5 mL/g substrat. pH 7 adalah pH yang paling sesuai digunakan untuk penghasilan hidrogen. Keamatan cahaya 5,000 lux adalah nilai optimum yang dapat memberikan penghasilan hidrogen tertinggi iaitu 80.21 mL hidrogen dengan hasil hidrogen 401.04 mL/g substrat. Penghasilan hidrogen didapati semakin menurun pada keamatan cahaya yang lebih tinggi daripada 5,000 lux.
Sisa puri pitaya merah bersama biji telah digunakan dalam penyediaan mufin yang dicampurkan dengan 10%, 15% dan 20% puri dalam formulasi bater. Ujian warna, kandungan jumlah polifenol, jumlah flavonoid, ujian antioksida; pemerangkapan radikal bebas 2,2-difenil-1-pikrilhidrazil (DPPH) dan ujian penurunan ferrik (FRAP) telah dijalankan. Warna bater 3 jenis mufin tersebut berwarna merah jambu violet. Warna merah jambu (nilai a) meningkat dengan signifikan (p<0.05) selaras peningkatan peratus kandungan puri manakala kecerahan (nilai L) menurun dengan peningkatan puri. Apabila dimasak, semua warna merah jambu daripada bater hilang. Permukaan mufin adalah lebih gelap (nilai L), dengan mufin 20% puri paling signifikan (p<0.05). Isi kesemua mufin berwarna kuning dan kecerahan (nilai L) didapati berkurang secara signifikan (p<0.05) dengan pertambahan peratus puri. Jumlah polifenol sampel mufin menunjukkan mufin 10% puri pitaya ekstrak air mengandungi jumlah polifenol yang paling tinggi (29.0 mg GAE/100 g sampel). Kandungan flavonoid menunjukkan mufin 20% puri pitaya mengandungi flavonoid yang paling signifikan (p<0.05) 15.3 mg katekin/100 g sampel berbanding mufin kawalan 11.0 mg katekin. Bagi ujian antioksida DPPH, semua mufin dengan puri pitaya menunjukkan peratus pemerangkapan yang lebih baik berbanding kawalan. Ujian FRAP menunjukkan pola yang serupa dengan keputusan mufin 10% (17.4), mufin 15% (15.4) dan mufin 20% (17.5 mg trolox/100 g sampel). Warna merah jambu bater mufin hilang semasa proses memasak namun nilai antioksida masih diperolehi dalam mufin masak.
Kajian ini dijalankan untuk menentukan isoterma dan kinetik penjerapan bahan pencemar boron daripada air sisa sintetik menggunakan batu kapur sebagai bahan penjerap berkos rendah. Penjerapan boron berlaku secara optimum pada julat pH6-8, masa sentuhan pada 90 min dan dos batu kapur 240 g/L yang penyingkirannya mencapai 40%. Isoterma penjerapan lebih diwakili oleh model Freundlich (R2 = 0.91) berbanding model Langmuir (R2 = 0.78) yang menunjukkan penjerapan secara multilapisan adalah dominan. Kajian kinetik penjerapan menunjukkan penjerapan boron ke atas batu kapur mematuhi dengan baik model penjerapan pseudo-tertib pertama (R2 = 0.93), pseudo-tertib kedua (R2 = 0.987), Elovich (R2 = 0.931) dan Intrapartikel (R2 = 0.960). Mekanisme penjerapan secara kimia adalah dominan berdasarkan nilai R2 yang paling tinggi bagi model pseudo-tertib kedua.
Kajian ini bertujuan untuk memilih kaedah terbaik daripada sebelas kaedah pengiraan Escherichia coli dalam masakan ayam. Kaedah-kaedah tersebut adalah piring curahan, piring sebaran, piring titisan, PetrifilmTM, tiga jenis pemiringan terus dan empat jenis kaedah bilangan paling mungkin (MPN). Perbandingan kaedah dijalankan mengikut prosedur ISO 16140. Setiap strain E. coli (ATCC 25922, IMR 1/3 107B dan IMR E243) telah diinokulasikan ke dalam lima jenis masakan ayam bagi mendapatkan kepekatan bakteria sehingga 105 cfu/g. Perlakuan haba dibuat pada 55oC selama
4-6 min bagi mewujudkan persekitaran yang seakan-akan sama seperti makanan tersebut dihidangkan sebaik sahaja selepas dimasak. Analisis statistik Regressi Kaedah Kuasa Dua Terkecil (KKDT) dijalankan bagi membandingkan sebelas kaedah pengiraan E. coli. Nilai kecerunan (m) yang signifikan (p < 0.05) pada kesemua Graf KKDT membawa maksud kesemua kaedah adalah serupa daripada segi kejituan, korelasi, dan ketepatan relatif. Oleh itu, penilaian praktikal turut dipertimbangkan bagi menentukan tiga kaedah terbaik bagi pengiraan E. coli dalam masakan ayam. Piring curahan, PetrifilmTM dan piring titisan adalah lebih praktikal berbanding lapan kaedah yang lain.
Kandungan logam berat Fe, Cu dan Mn dalam tanih serta tumbuhan Nepenthes sp yang diambil daripada kawasan bekas lombong bijih timah dan besi di Lombong Pelepah Kanan, Kota Tinggi, Johor telah dikaji. Kandungan logam berat telah ditentukan di dalam empat bahagian tumbuhan Nepenthes sp. iaitu di dalam akar, batang, daun dan periuk. Sebanyak 15 sampel tumbuhan Nepenthes sp dan tanih dikumpul untuk dianalisis. Komposisi logam-logam berat dalam sampel tanih diekstrak dengan menggunakan campuran asid nitrik dan asid perklorik. Kandungan logam berat dalam tumbuhan pula diekstrak melalui kaedah penghadaman basah. Kandungan logam berat di dalam larutan ekstrak tanih dan tumbuhan ditentukan dengan menggunakan alat Spektrofotometer Serapan Atom Kaedah Nyalaan (FAAS). Nilai Koefisien Penyerapan Biologi (BAC) dikira sebagai nisbah kandungan logam berat dalam tumbuhan kepada kandungan logam berat dalam tanih. Analisis tanih menunjukkan kawasan bekas lombong didominasi oleh pasir dan bersifat asid. Ia juga mempunyai kandungan bahan organik dan nilai kekonduksian elektrik yang rendah. Logam Fe mencatatkan kepekatan purata paling tinggi di dalam tanih diikuti oleh Mn dan Cu. Tumbuhan Nepenthes sp boleh dijadikan sebagai pengumpul biologi untuk logam Fe kerana nilai BACnya adalah tinggi.
Kajian ini bertujuan untuk mereka bentuk dan mengkaji prestasi pengumpul fotovoltan-terma (PV/T) dengan menggunakan
reka bentuk pengumpul terma aliran air secara pilin. Reka bentuk pengumpul terma aliran air secara pilin telah dibina
semula daripada reka bentuk penyelidik sebelum ini. Pengumpul terma ini menggunakan saiz tiub yang lebih besar dan
jarak antara tiub lebih dekat berbanding dengan reka bentuk penyelidik sebelum ini. Pengumpul PV/T ini telah diuji di
bawah tiga keamatan yang berbeza iaitu 300, 500 dan 700 W/m2 serta diuji pada kadar aliran jisim air yang berbeza
iaitu 0.01, 0.02 dan 0.04 kg/s. Pada keadaan yang sama, kecekapan fotovoltan, terma dan tergabung juga menunjukkan
nilai yang paling tinggi, iaitu 4.18%, 76.68% dan 80.86%. Kecekapan terma yang dihasilkan pada kajian ini lebih tinggi
dibandingkan dengan kajian sebelumnya.
For most natural or naturally-derived liquid products, their color reflects on their quality and occasionally affects customer preferences. To date, there are a few subjective and objective methods for color measurement which are currently utilized by various industries. Researchers are also improving these methods and inventing new methods, as color is proven to have the ability to provide various information on the condition and quality of the liquid. However, a review on the methods, especially for amber-colored liquid, has not been conducted yet. This paper presents a comprehensive review on the subjective and objective methods for color measurement of amber-colored liquids. The pros and cons of the measurement methods, the effects of the color on customer preferences, and the international industry standards on color measurements are reviewed and discussed. In addition, this study elaborates on the issues and challenges related to the color measurement techniques as well as recommendations for future research. This review demonstrates that the existing color measurement technique can determine the color according to the standards and color scales. However, the efforts toward minimizing the complexity of the hardware while maximizing the signal processing through advanced computation are still lacking. Therefore, through this critical review, this review can hopefully intensify the efforts toward finding an optimized method or technique for color measurement of liquids and thus expedite the development of a portable device that can measure color accurately.
Populations of the Bornean gliding lizard, Draco cornutus, differ markedly in the colour of their gliding membranes. They also differ in local vegetation type (mangrove forest versus lowland rainforest) and consequently, the colour of falling leaves (red and brown/black in mangrove versus green, brown and black in rainforest). We show that the gliding membranes of these lizards closely match the colours of freshly fallen leaves in the local habitat as they appear to the visual system of birds (their probable predators). Furthermore, gliding membranes more closely resembled colours of local fallen leaves than standing foliage or fallen leaves in the other population's habitat. This suggests that the two populations have diverged in gliding membrane coloration to match the colours of their local falling leaves, and that mimicking falling leaves is an adaptation that functions to reduce predation by birds.
PURPOSE: The objective of this study was to determine the visual function of colour-deficient subjects when wearing special red tint contact lenses.
MATERIALS AND METHODS: A total of 17 subjects with congenital colour vision deficiency (14 deutans and 3 protans), voluntarily participated in this study. The average age for the subjects was 23.00 ± 4.06 years old. Visual functions tested were visual acuity (LogMAR), contrast sensitivity (FACT Chart) and stereopsis (TNO and Howard Dolman tests). Two types of special red tint lenses were used in this study; Type I (light red) and Type II (dark red).
RESULTS: The protans and deutans showed no significant changes in visual acuity and contrast sensitivity when wearing either type of contact lens. Stereopsis testing using the Horward-Dolman test gave no significant changes but significant differences were seen using the TNO test. Stereopsis using the TNO test was significantly poorer with the red tinted contact lenses compared to without for both protons and deutans. Testing binocularly with Ishihara plates showed that 88% (n=15) of patients passed the test with Type I and Type II contact lenses. When D15 test was done, 3 patients (17.6%) were 'normal' when using the Type I contact lenses and 2 patients (11.8%) were 'normal' when using the Type II contact lenses. However, with FM100Hue test, most patients showed deutan responses. Total error scores (TES) were found to be higher with Type I and Type II contact lenses compared to without.
CONCLUSIONS: The Type I and II special tinted contact lens used in this study did not cause a reduction of visual acuity and contrast sensitivity for the colour defects. Stereopsis was also not reduced with the Type I and Type II contact lenses for the colour defects except when tested with the TNO test. Colour vision defects became difficult to detect using the Ishihara plates but FM100Hue test did not show any improvement with the Type I and Type II contact lenses.
Matched MeSH terms: Color; Color Vision Defects/rehabilitation*
This study was conducted for 3 main purposes: 1) to determine if there was blue colour deficiency amongst diabetes mellitus (IDDM and NIDDM) patients without retinopathy, 2) to determine if the Dl5 test could be used to detect any colour vision defects amongst diabetics without retinopathy (all previous workers have used FM 100-Hue), and 3) to assess the performance of diabetics without retinopathy in detecting correct colour changes with the urine strip test. Thirty eight non-insulin dependent diabetes mellitus (NIDDM) and 30 insulin-dependent diabetes mellitus (IDDM) patients without retinopathy participated in this study. A control group of 23 normal subjects were also included in the study. Dl5 colour vision test was performed under daylight conditions. Colour dependent urine glucose test (Glukotest) was also performed on all subjects. The study showed that 47.1% of diabetics (47.4% NIDDM and 46.7% IDDM patients) without retinopathy had a blue colour deficiency. Amongst the diabetics with a blue colour deficiency, 25% of diabetics (22% of NIDDM and 28.6% of IDDM patients) failed to accurately match the strip colour with the comparison chart on the bottle.
Kajian ini dilakukan untuk 3 tujuan: I) untuk menentukan samada terdapat gangguan penglihatan warna biru dalam pesakit diabetes mellitus (IDDM dan NIDDM) tanpa retinopati, 2) untuk menentukan samada ujian penglihatan warna Dl5 boleh digunakan untuk mengesan defek penglihatan warna dalam pesakit diabetes tanpa retinopati (kesemua kajian terdahulu menggunakan ujian FM 100-Hue). dan 3) untuk menilaikan prestasi pesakit diabetik tanpa retinopati dalam mengesan perubahan warna yang betul dengan menggunakan ujian strip urin. Tiga puluh lapan pesakit dengan non-insulin dependent diabetes (NIDDM) dan 30 pesakit dengan insulin dependent diabetes (IDDM) tanpa retinopati menyertai kajian ini. Kumpulan kawalan mengandungi 23 orang subjek yang normal juga terlibat di dalam kajian ini. Ujian penglihatan warna Dl5 dilakukan di bawah cahaya daylight. Ujian glukos urin berasaskan warna (Glukotest) dilakukan ke atas semua subjek. Kajian menunjukkan 47.1% pesakit diabetes (47.4% pesakit NIDDM dan 46.7% pesakit IDDM) tanpa retinopati mengalami defisiensi warna biru. Dalam kumpulan diabetik dengan defisiensi warna biru, 25% pesakit diabetes (22.2% adalah pesakit NIDDM dan 28.6% adalah pesakit IDDM) gagal untuk memadankan dengan tepat warna strip dengan carta perbandingan warna di atas botol.
Matched MeSH terms: Color; Color Vision Defects; Color Vision
Polyporus sp. S133 decolorized the Amaranth in 72 h (30 mg L(-1)) under static and shaking conditions. Liquid medium containing glucose has shown the highest decolorization of Amaranth by Polyporus sp. S133. When the effect of increasing inoculum concentration on decolorization of Amaranth was studied, maximum decolorization was observed with 15 % inoculum concentration. Significant increase in the enzyme production of laccase (102.2 U L(-1)) was observed over the period of Amaranth decolorization compared to lignin peroxidase and manganese peroxidase. Germination rate of Sorghum vulgare and Triticum aestivum was less with Amaranth treatment as compared to metabolites obtained after its decolorization. Based on the metabolites detected by GC-MS, it was proposed that Amaranth was bio-transformed into two intermediates, 1-hydroxy-2-naphthoic acid and 1,4-naphthaquinone. Overall findings suggested the ability of Polyporus sp. S133 for the decolorization of azo dye and ensured the ecofriendly degradation of Amaranth.
The aim of this study was to evaluate colour stability upon exposure to spices of a nano-filled and a micro-hybrid resin composite finished either with Sof-Lex™ discs (SLD) or against plastic strips (PS).
An improvement to the previously proposed Canny optimization technique for scanning electron microscope image colorization is reported. The additional process is adaptive tuning, where colour tuning is performed adaptively, based on comparing the original luminance values with calculated luminance values. The complete adaptive Canny optimization technique gives significantly better mechanical contrast on scanning electron microscope grey-scale images than do existing methods.
Optimization of decolorization of methylene blue (MB) dye by lignin peroxidase (LiP) enzyme produced by white-rot fungus Phanerochaete chrysosporium using sewage treatment plant (STP) sludge as a major substrate was carried out in the laboratory. Optimization by the one-factor-at-a-time (OFAT) and statistical approach was carried out to determine the process conditions on optimum decolorization of MB dye using LiP enzyme in static mode. The OFAT method indicated that the optimum conditions for decolorization of MB dye (removal: 14-40%) was at temperature 55 degrees C, pH 5.0 with hydrogen peroxide (H(2)O(2)) concentration 4.0mM, MB dye concentration 20mg/L and LiP activity 0.487U/ml. The addition of veratryl alcohol to the reaction mixtures did not contribute any further increases in decolorization. The initial concentration of MB and the activity of LiP enzyme were further optimized using response surface methodology (RSM). The contour and surface plots suggested that the optimum initial concentration of MB and LiP activity predicted were 15mg/L and 0.687U/ml, respectively for the removal of 65%. The validation of the model showed that the decolorization process gave the higher removal of 90% in agitation mode compared to the static mode with 65% for 60min of incubation time by LiP enzyme.
The purpose of this study was to optimise the testing paradigm for isolating the contributions of chromatic and achromatic mechanisms to the human spectral sensitivity function. Spectral sensitivity was determined for a test spot size of 1.2 deg presented with various spatial and temporal masks on a large, 10 deg background field of moderate intensity (1000 td) and colour temperature, CT = 2700 K. Sinusoidal temporal presentation (1 Hz) and a masking annulus of between 3 and 10 min of arc surrounding the test spot, was found to be most effective in separating chromatic from achromatic mechanisms. Square-wave (1 Hz) temporal presentation combined with the annulus was slightly less selective. The presence of the annulus did not affect the shape of flicker detection at 25 Hz which is a measure of the luminosity (achromatic) spectral sensitivity function.
Sexual ornamentation needs to be conspicuous to be effective in attracting potential mates and defending territories and indeed, a multitude of ways exists to achieve this. Two principal mechanisms for increasing conspicuousness are to increase the ornament's colour or brightness contrast against the background and to increase the size of the ornament. We assessed the relationship between the colour and size of the dewlap, a large extendible throat-fan, across a range of species of gliding lizards (Agamidae; genus Draco) from Malaysia and the Philippines. We found a negative relationship across species between colour contrast against the background and dewlap size in males, but not in females, suggesting that males of different species use increasing colour contrast and dewlap size as alternative strategies for effective communication. Male dewlap size also increases with increasing sexual size dimorphism, and dewlap colour and brightness contrast increase with increasing sexual dichromatism in colour and brightness, respectively, suggesting that sexual selection may act on both dewlap size and colour. We further found evidence that relative predation intensity, as measured from predator attacks on models placed in the field, may play a role in the choice of strategy (high chromatic contrast or large dewlap area) a species employs. More broadly, these results highlight that each component in a signal (such as colour or size) may be influenced by different selection pressures and that by assessing components individually, we can gain a greater understanding of the evolution of signal diversity.
The genera Parandrocephalus Heller, 1916 and Hexamitodera Heller, 1896 are reviewed and redescribed. Based on the combination of chromatic sexual dimorphism, velvety pubescence on the whole dorsal body and distinctly developed carina on the elytra, Parandrocephalus blairi Bentanachs & Vives, 2009 is transferred to Hexamitodera. A new subgenus, Sulcognatha Perger, is instituted to accommodate mandible, head and metasternal modifications in Hexamitodera blairi comb. n. that are lacking in the type species of Hexamitodera, Hexamitodera semivelutina. As indicated by fundamental structural differences in the mandibles of Parandrocephalus and Hexamitodera (Sulcognatha) blairi comb. n., the exaggerated secondary sexual traits and open procoxal cavities in both taxa are presumably the result of convergent evolution. Contrary to Bentanachs & Vives (2009), the presence of the two Parandrocephalus species in Sundaland and the endemism of Hexamitodera on Sulawesi agree well with the zoogeographical separation of both areas by the Wallace line.
Foreground detection has been used extensively in many applications such as people counting, traffic monitoring and face recognition. However, most of the existing detectors can only work under limited conditions. This happens because of the inability of the detector to distinguish foreground and background pixels, especially in complex situations. Our aim is to improve the robustness of foreground detection under sudden and gradual illumination change, colour similarity issue, moving background and shadow noise. Since it is hard to achieve robustness using a single model, we have combined several methods into an integrated system. The masked grey world algorithm is introduced to handle sudden illumination change. Colour co-occurrence modelling is then fused with the probabilistic edge-based background modelling. Colour co-occurrence modelling is good in filtering moving background and robust to gradual illumination change, while an edge-based modelling is used for solving a colour similarity problem. Finally, an extended conditional random field approach is used to filter out shadow and afterimage noise. Simulation results show that our algorithm performs better compared to the existing methods, which makes it suitable for higher-level applications.