426 research outputs found

    Comparative analysis of conventional versus modern appraisal systems: an empirical evidence from telecom sector of Pakistan

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    Current study aims at investigating the comparison of online performance appraisal system in relation with Traditional paper and pencil based performance appraisal system on employees’ work outcome and behavior. In this way, the contemporary study will focus on major areas of online performance appraisal system and paper and pencil based performance appraisal system. The universe selected for this study is telecommunication industry of Pakistan and two stage sampling is used to conduct the study. First all the telecommunication and cellular companies were the population and then PTCL was finally selected for study purpose. The results showed that there is a significance difference between the responses of the manual and online respondents and it is very clear that the employees consider online based performance appraisal system to be more beneficial and accurate with respect to the above mentioned six constructs

    ChatGPT Performance on Standardized Testing Exam -- A Proposed Strategy for Learners

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    This study explores the problem solving capabilities of ChatGPT and its prospective applications in standardized test preparation, focusing on the GRE quantitative exam. Prior research has shown great potential for the utilization of ChatGPT for academic purposes in revolutionizing the approach to studying across various disciplines. We investigate how ChatGPT performs across various question types in the GRE quantitative domain, and how modifying question prompts impacts its accuracy. More specifically this study addressed two research questions: 1. How does ChatGPT perform in answering GRE-based quantitative questions across various content areas? 2. How does the accuracy of ChatGPT vary with modifying the question prompts? The dataset consisting of 100 randomly selected GRE quantitative questions was collected from the ETS official guide to GRE test preparation. We used quantitative evaluation to answer our first research question, and t-test to examine the statistical association between prompt modification and ChatGPT's accuracy. Results show a statistical improvement in the ChatGPT's accuracy after applying instruction priming and contextual prompts to the original questions. ChatGPT showed 84% accuracy with the modified prompts compared to 69% with the original data. The study discusses the areas where ChatGPT struggled with certain questions and how modifications can be helpful for preparing for standardized tests like GRE and provides future directions for prompt modifications

    Caracterización metódica de aceite de salvado de arroz (Oryza sativa) de Pakistán

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    The hexane-extracted oil content of four varieties of rice (Oryza sativa) viz. Super Kernel, 386, 385 and Basmati, bran was ranged 14.70-19.10 %. Other physical and chemical parameters of the extracted oils were as follow: Iodine value 112.40, 109.80, 105.1 and 103.70; refractive index ( 40 °C ) 1.4650, 1.4680, 1.4657 and 1.4660; density ( 40 °C ) 0.919, 0.913, 0.909 and 0.911; saponification value 183, 177, 186 and 190; unsaponifiable matter 6.15, 5.60, 4.98 and 5.40 % respectively. Tocopherols ( α, γ and δ) in the oils were: 284.00, 175.12, 180.42, 300.06; 83.40, 98.70, 120.70, 90.60; 75.16, 57.20, 39.32, 83.00 mg/kg respectively. The contents of tocotrienols ( α, γ and δ) in the oils were: 120.30, 106.00, 95.20, 135.74; 196.00, 125.00, 210.0, 276.41; 72.50, 20.00, 39.30, 64.00 mg/kg respectively. The amount of γ - Oryzanol in the investigated oils was ranged 415.12-802.05 The induction periods (Rancimat, 20 L/h, 120 °C ) of the crude oils were 6.81, 5.99, 6.39 and 7.40 h respectively. The major sterol fractions of the oils consisted of campesterol ranged (10.10-19.20%), stigmasterol (14.00-19.28 %), b -sitosterol (49.30-58.20 %), and D5 ,avenasterol (8.14-13.05 %). The investigated varieties ( Super Kernel, 386, 385 and Basmati) of rice bran oil were found to contain high levels of oleic acid 42.67, 38.59, 40.68 and 36.78 % followed by linoleic and palmitic acids 31.58, 33.80, 28.70, 30.51 and 17.00, 14.88, 19.63, 20.00 % respectively. The contents of myristic, stearic and arachidic acids was 1.50, 2.02, 4.28, 1.00; 2.64, 2.87, 4.02, 7.48; and 1.28, 3.00, 1.00, 1.00 % respectively. A number of parameters of the investigated rice bran oils indigenous to Pakistan were comparable to those of typical rice bran and some other vegetable oils, reported in the literature. The results of the present analysis as compared with those of different vegetable oils demonstrated rice bran to be a potential oil source and thus could be useful for the establishment of a globalized database of this valuable crop.El contenido de aceite, extraído con hexano, del salvado de cuatro variedades de arroz (Oryza sativa) viz. Super Kernel, 386, 385 y Basmati, varió entre el 14.70 y el 19.10 %. Otros parámetros físicos y químicos de los aceites extraídos fueron respectivamente: Indice de yodo: 112.40, 109.80, 105.1 y 103.70; índice de refracción ( 40 °C ): 1.4650, 1.4680, 1.4657 y 1.4660; densidad ( 40 °C ) 0.919, 0.913, 0.909 y 0.911; índice de saponificación: 183, 177, 186 y 190; insaponificable: 6.15, 5.60, 4.98 y el 5.40 %. Los tocoferoles ( α, γ, δ) en los aceites fueron, respectivamente: 284.00, 175.12, 180.42, 300.06; 83.40, 98.70, 120.70, 90.60; 75.16, 57.20, 39.32 y 83.00 mg/kg. El contenido de tocotrienoles ( α, γ, δ) en los aceites fue: 120.30, 106.00, 95.20, 135.74; 196.00, 125.00, 210.0, 276.41; 72.50, 20.00, 39.30 y 64.00 mg/kg, respectivamente. En los aceites estudiados se encontró una concentración de γ -oryzanol que varió entre 415.12 y 802.05 µg/g . Los periodos de inducción (Rancimat, 20 L/h, 120 °C ) de los aceites crudos fueron 6.81, 5.99, 6.39 y 7.40 h, respectivamente. Las fracciones principales de esteroles en los aceites se componían de: campesterol (10.10-19.20 %), stigmasterol (14.00-19.28 %), b -sitosterol (49.30-58.20 %) y Δ5 ,avenasterol (8.14-13.05 %). Las variedades investigadas ( Super Kernel, 386, 385 and Basmati) de aceite de salvado de arroz contenían elevados niveles de acido oleico 42.67, 38.59, 40.68 y 36.78 % seguido por los ácidos linoleico y palmítico 31.58, 33.80, 28.70, 30.51; 17.00, 14.88, 19.63 y 20.00 %, respectivamente. Los contenidos en ácidos mirístico, esteárico y araquídico fueron 1.50, 2.02, 4.28, 1.00; 2.64, 2.87, 4.02, 7.48; 1.28, 3.00, 1.00 y 1.00 % respectivamente. Los valores encontrados en los parámetros de los salvados de arroz investigados de procedencia Paquistaní son parecidos a los encontrados en la literatura de otros salvados de arroz y de aceites extraídos de verduras. Los resultados del presente análisis, al igual que los similares obtenidos de aceites de diferentes verduras, han demostrado que el salvado de arroz podría ser una fuente potencial de aceite y también podrían ser útiles para el establecimiento de una base de datos globalizada de esta valiosa cosecha

    High-Value Components and Bioactives from Sea Cucumbers for Functional Foods—A Review

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    Sea cucumbers, belonging to the class Holothuroidea, are marine invertebrates, habitually found in the benthic areas and deep seas across the world. They have high commercial value coupled with increasing global production and trade. Sea cucumbers, informally named as bêche-de-mer, or gamat, have long been used for food and folk medicine in the communities of Asia and Middle East. Nutritionally, sea cucumbers have an impressive profile of valuable nutrients such as Vitamin A, Vitamin B1 (thiamine), Vitamin B2 (riboflavin), Vitamin B3 (niacin), and minerals, especially calcium, magnesium, iron and zinc. A number of unique biological and pharmacological activities including anti-angiogenic, anticancer, anticoagulant, anti-hypertension, anti-inflammatory, antimicrobial, antioxidant, antithrombotic, antitumor and wound healing have been ascribed to various species of sea cucumbers. Therapeutic properties and medicinal benefits of sea cucumbers can be linked to the presence of a wide array of bioactives especially triterpene glycosides (saponins), chondroitin sulfates, glycosaminoglycan (GAGs), sulfated polysaccharides, sterols (glycosides and sulfates), phenolics, cerberosides, lectins, peptides, glycoprotein, glycosphingolipids and essential fatty acids. This review is mainly designed to cover the high-value components and bioactives as well as the multiple biological and therapeutic properties of sea cucumbers with regard to exploring their potential uses for functional foods and nutraceuticals

    Methane and n-hexane ignition in a newly developed diaphragmless shock tube

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    Shock tubes have been routinely used to generate reliable chemical kinetic data for gas-phase chemistry. The conventional diaphragm-rupture mode for shock tube operation presents many challenges that may ultimately affect the quality of chemical kinetics data. Numerous diaphragmless concepts have been developed to overcome the drawbacks of using diaphragms. Most of these diaphragmless designs require significant alterations in the driver section of the shock tube and, in some cases, fail to match the performance of the diaphragm-mode of operation. In the present work, an existing diaphragm-type shock tube is retrofitted with a fast-acting valve, and the performance of the diaphragmless shock tube is evaluated for investigating the ignition of methane and n-hexane. The diaphragmless shock tube reported here presents many advantages, such as eliminating the use of diaphragms, avoiding substantial manual effort during experiments, automating the shock tube facility, having good control over driver conditions, and obtaining good repeatability for reliable gas-phase chemical kinetic studies. Ignition delay time measurements have been performed in the diaphragmless shock tube for three methane mixtures and two n-hexane mixtures at P5P_5 = 10 - 20 bar and T5T_5 = 738 - 1537 K. The results obtained for fuel-rich, fuel-lean, and oxygen-rich (undiluted) mixtures show very good agreement with previously reported experimental data and literature kinetic models (AramcoMech 3.0 [1] for methane and Zhang et al. mechanism [2] for n-hexane). The study presents an easy and simple method to upgrade conventional shock tubes to a diaphragmless mode of operation and opens new possibilities for reliable chemical kinetics investigations.Comment: 22 pages, 9 figure

    Dual-camera high-speed imaging of n-hexane oxidation in a high-pressure shock tube

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    Shock tubes are widely used in the study of chemical kinetics. Its benefits rely on the almost ideal shock-heating process that provides high temperatures and pressures to a chemical system for a limited test time. Just like any reactor, shock tubes are not immune to non-ideal effects. The study of conditions that might deviate experiments from ideal conditions is thus of the utmost importance. High-speed imaging has been proven to be a powerful bytool to analyze non-ideal / non-homogenous combustion in shock tubes. In this work, dual-camera high-speed imaging experiments were performed at 10, 15 and 20 bar in a high-pressure shock tube (HPST). An optical section was designed as an extension of the HPST which enabled simultaneous visualization from the endwall and the sidewall of the driven section of the shock tube. n-Hexane, a fuel with a negative temperature coefficient (NTC) behavior that has been identified as prone to non-homogenous ignition, is used as a test fuel. Reactive mixtures and thermodynamic conditions were selected to visually analyze ignition processes at the high-temperature, NTC and low-temperature regimes. Non-homogeneous ignition was observed mostly at the local maximum of the IDT, which is comprised by the high-temperature and NTC regions. Stoichiometric n-hexane mixture with high fuel loading (5% n-hexane) presented the highest deviation from constant volume chemical kinetic simulations. The inclusion of helium as a bath gas to mitigate preignition was tested and it showed to improve the susceptibility of the mixtures to develop reaction fronts. The modified Sankaran criterion for the identification of ignition regimes in shock tubes was tested and it showed an overall good agreement against the experimental observations.Comment: 23 pages, 11 figures, 1 tabl

    Determinación mediante pruebas aceleradas y a temperatura ambiente de la actividad antioxidante de varios extractos de plantas en aceite de girasol

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    The present study was conducted to investigate the antioxidant potential of 11 medicinally or economically important plant materials indigenous to Pakistan. The materials were extracted with 80% methanol and examined  for their antioxidant activity under different storage conditions using sunflower and soybean oils as oxidation substrates. Preliminary antioxidant activity assessment among the extracts was conducted with the TLC-test and by measuring percent inhibition of linoleic acid peroxidation. The rhizome of Iris germanica, leaves of Lawsonia alba, and M. oleifera, coffee (Coffee arabica) beans, rice (Oryza sativa) bran, wheat bran and oats (Avenis sativa) groats and hull, which showed higher antioxidant activity among the extracts, were further evaluated using soybean and sunflower oils as oxidation substrates. The vegetable oils were stabilized with extracts at a dosage of 0.12% (w/w), and individually subjected to accelerated (65 oC, 15 days) and ambient (6 months) storage. The oxidative deterioration level was monitored for the measurement of antioxidant activity index (AI), peroxide value (PV), conjugated dienes and trienes contents. Overall, the extracts of coffee beans, oat groats and hull, Iris germanica and M. oleifera leaves were found to be the most effective in extending oxidative stability, and retarding PV, primary and secondary oxidation products of soybean and sunflower oils. The order of efficiency of the plant extracts for stabilization of the subject oils was as follows: oat groats and hull > coffee beans > M. oleifera leaves > Lawsonia alba > Iris germanica > rice bran > wheat bran. Significant differences in the antioxidant potential of some of the extracts for stabilization of substrate oils were observed under ambient and accelerated storage conditions and thus demonstrated a variable antioxidant prospective of the extracts under different analytical protocols.El presente trabajo se ha realizado para investigar la capacidad antioxidante potencial de once plantas medicinales o económicamente importantes autónomas del Pakistán. Las plantas se extractaron con metanol al 80% y se estudia su capacidad antioxidante bajo diferentes condiciones de almacenamiento, utilizando aceite de girasol y soja como sustratos. Los ensayos previos de capacidad antioxidante se llevaron a cabo con la prueba TLC-test y midiendo el porcentaje de inhibición de la peroxidación del ácido linoleico. El rizoma de Iris germanica, las hojas de Lawsonia alba, y M. oleifera, las semillas de café (Coffee arabica), el salvado de arroz (Oryza sativa), el salvado de trigo y salvado, granos y cáscara de avena (Avenis sativa), que fueron las que tuvieron una mayor capacidad antioxidante, de todos los extractos, se ensayaron después usando los sustratos de girasol y soja. Los aceites vegetales se estabilizaron con una dosis de 0,12 (peso/peso) y se sometieron a ensayos de almacenamiento acelerados (15 días a 65º) o temperatura ambiente (6 meses). El deterioro oxidativo se siguió mediante la medida del índice de actividad (AI), índice de peróxido (PV), así como por el contenido de dienos y trienos. En general, los extractos de semillas de café, partículas y cáscaras de avena, y Iris germanica y hojas de M. oleifera fueron las que mostraron una mayor efectividad para extender la estabilidad de los aceites, y retardar la elevación del PV, así como en la prevención de la aparición de productos de oxidación primarios y secundarios. El orden de eficacia fue: partículas y cáscaras de avena > granos de café > hojas de M. oleifera > Lawsonia alba > Iris germanica > salvado de arroz > salvado de trigo. Se detectaron diferencias significativas en el potencial antioxidante de algunos extractos tanto a temperatura ambiente como en condiciones de las pruebas aceleradas. Ello demostró una amplia gama de propiedades antioxidante de los extractos frente a los diferentes procedimientos analíticos empleados

    Evaluación de la calidad del aceite de semilla de Moringa concanensis extraído mediante disolvente y adición de enzimas

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    The composition and quality of the M. concanensis seed oil extracted through an aqueous-enzyme-assisted technique, using three commercial enzyme-mixtures (Natuzyme, Kemzyme, and Feedzyme) was compared to those of the control-, (without enzymes) and solvent-extracted oils. Aqueous enzyme-extracted M.concanensis seed oil content ranged from 23.54 to 27.46% and was significantly (P 0.05) variation in the contents of fiber and ash within the three extraction methods. However, the protein content of the meal obtained through the aqueous-enzyme and control methods was significantly (P 0,05) en el contenido de fibra y ceniza para los tres métodos de la extracción. Sin embargo, el contenido proteínico de la harina obtenido por métodos enzimáticos y el control sin enzimas fue significativamente menor (P < 0,05) que el de la harina obtenida después de la extracción por disolvente. Las diferencias en el índice de yodo (67.1-68.0 g /100 g of oil), densidad en 24 °C (0,865-0,866 g/mL), índice de refracción a 40 °C (1,4622-1,4627) y fracción insaponificable (0,69-0,76 %) no fueron significativamente diferentes para ninguna de las técnicas de extracción. Las extinciones específicas en 232 y 270 nm, el índice de peróxidos, el índice de p-anisidina, la acidez libre y el color de los aceites extraídos con enzimas fueron inferiores a los del aceite obtenido mediante extracción con disolvente. La composición en ácidos grasos de los aceites fue similar en todas los aceites encontrándose sólo pequeñas en los contenidos de ácido esteárico y linoleico. Respecto a los tocoferoles, el contenido en g-tocoferol fue similar en el control y en las extracciones con enzimas y significativamente más elevado (P < 0.05) que en el aceite extraído con disolvente, mientras que el contenido en a-tocoferol fue superior en el aceite extraído con disolvente

    Inter-varietal variation in the composition of seeds and seed oils from winter mel on [Benincasa Hispida (thunb.) cogn.] fruits.

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    Winter melon (Benincasa hispida), locally known as Kundur, is a vegetable crop, popular, especially among Asian communities both for nutritional and medicinal attributes. In the present work, physicochemical properties of seeds and the extracted seed oils were examined and compared among three cultivars namely round, oval and hybrid of winter melon. The seeds from round, oval and hybrid fruits, exhibited protein, fiber and ash contents 28.18-42.03, 19.36-26.21 and 5.02- 11.81%, respectively. The oils were extracted based on Soxhlet method by petroleum ether, whilst yields ranged from 17.78- 32.53% (wt/wt). The extracted oils were analyzed for physicochemical parameters, and fatty acids, tocopherols and sterols profiles. The results for specific gravity (25°C), refractive index (nD 25°C), iodine value (IV), saponification value (SV), peroxide value (PV), and free fatty acid (% as oleic acid) were 0.89-0.91 g/mL, 1.4627-1.4646, 119.9-125.1 g I/100 g oil, 182.3-194.1 mg KOH/ g oil, 1.13-1.33 mequiv.O2 /kg, 1.57-2.10%, respectively. The oil color intensity in terms of yellow and red units was 6.9Y + 1.0 R to 8.9Y + 1.9R. The amounts of oil tocopherols as analyzed by HPLC varied widely among the cultivars tested showing &#945;-tocopherol 31.1-207.6 mg/kg and &#948;-tocopherol 60.4-146.0 mg/kg. According to the GLC analysis linoleic acid (C18:2) was established to be the principal fatty acid (63.10-70.64%) followed by C16:0 (12.45-17.59), C18:1 (8.46-12.87%) and C18:0 (5.13-7.48%). Analysis of oil sterol fractions, using GC and GC-MS, revealed the presence of &#946;-sitosterol (54.62–60.50%), campesterol (15.10–18.50%), stigmasterol (11.00–14.30% and &#916; 5 -avenasterol (6.40–8.14 %) as the four main components. Most of the properties of the seed oils analyzed varied significantly among fruit cultivars tested. Overall, we concluded that the seeds, which are under-utilized and often discarded as an agrowate, from winter melon should be explored for extraction of high-linoleic oil with additional tocopherols and phytosterol benefits
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