48 research outputs found
Effect of gonadotropin-releasing hormone (GnRH) treatment on multiple births in Afshari ewes
The purpose of this study was to investigate the effects of gonadotropin-releasing hormone (GnRH) administration on the induction of multiple births in synchronized Afshari ewes. 16 cycling, multiparous fat-tailed Iranian Afshari ewes, weighing 66.5 ± 2.5 kg, were used in the trail. Estrus was synchronized using controlled internal drug release CIDR’s; inserted for 14 days. Pregnant mare serum gonadotrophin (PMSG) (300 IU) was injected to ewes a day before CIDR removal. The ewes was randomly allocated to two groups (n = 8). Synchronization treatment was initiated with a week interval in two groups (weeks 1 and 2). 24 h following CIDR removal (day 1), GnRH (50 μg) was administered to half of each group ewes (GnRH and control groups), and ewes mated with the proven rams. Pregnancy was diagnosed with the aid of transabdominal ultrasonograpy 30 days after mating. Ovarian follicular activity was monitored with the aid of transrectal ultrasonograpy on the days of CIDR removal and at estrus (approximately day 1). Following PMSG treatment, the mean number of large follicles on total ovaries increased from CIDR removal to estrus 1.48 ± 0.71 vs. 2.85 ± 0.82 (P < 0.05). Lambing rate in GnRH group (162.5%) was higher (P < 0.05) compared to the control group (125%). The mean weights of lambs born in the GnRH and control groups were 5.5 ± 0.1 and 5.2 ± 0.1, respectively.Key words: GnRH, estrus synchronization, Afshari, ewe, lambing rate
The effects of pregnant mare serum gonadotropin (PMSG) injection a day prior or at controlled intravaginal drug-releasing (CIDR) removal on multiple births in Afshari ewes
According to the importance of lambing rate to profitability of sheep holders, this trial investigated the effects of pregnant mare serum gonadotropin (PMSG) injection a day prior or at controlled intravaginal drug-releasing device (CIDR) removal on multiple births in synchronized Afshari ewes. 16 cycling, multiparous fat-tailed Iranian Afshari ewes, weighing 66.5±2.5 kg, were used in the trial. The ewes were randomly allocated in equal numbers (n = 8) to two treatment groups. The estrous cycles were synchronized using CIDR’s inserted for a period of 14 days. In a group (PMSG/ d -1) of ewes, PMSG (300 IU) intramuscularly (IM) was injected a day (day = -1) prior to CIDR removal (day 0 = day of CIDR removal) and another group (PMSG/ d 0) received PMSG at CIDR removal (day 0). 48 following CIDR removal (day 1), GnRH (50 μg) was administered to half of each group of ewes and ewes were mated with the proven rams. Ovarian follicular activity was monitored with the aid of transrectal ultrasonograpy: on the day of CIDR removal (day 0) and a day later (at estrus, day 1). Pregnancy was diagnosed with the aid of transabdominal ultrasonograpy 30 days after mating. Following PMSG (day = -1) treatment, the mean number of large follicles on both ovaries increased from CIDR removal to estrus (1.50±0.61 vs. 2.78±0.69) (P < 0.05). Lambing rate in PMSG/ d -1+GnRH, PMSG/ d -1 noGnRH, PMSG/ d0+GnRH and PMSG/ d0 noGnRH groups was 175, 125, 175 and 150% respectively. The results show that PMSG injection a day prior or at CIDR removal, caused large follicles development, but no significant difference was seen between the two treatment lambing rates and also, the lambing rate increased in group treated with GnRH.Key words: Pregnant mare serum gonadotropin (PMSG), gonadotropin-releasing hormone (GnRH), Afshari ewes, lambing
Rectal cancer treatment and outcome in the elderly: an audit based on the Swedish rectal cancer registry 1995–2004
<p>Abstract</p> <p>Background</p> <p>Limited information is available regarding the effect of age on choice of surgical and oncological treatment for rectal cancer. The objective of this study was to assess the influence of age on treatment and outcome of rectal cancer.</p> <p>Methods</p> <p>We utilized data in the Swedish Rectal Cancer Registry (SRCR) from patients treated for rectal cancer in Sweden in 1995–2004.</p> <p>Results</p> <p>A total of 15,104 patients with rectal cancer were identified, 42.4% of whom were 75 years or older. Patients ≥75 years were less likely to have distant metastases than younger patients (14.8% vs. 17.8%, <it>P </it>< 0.001), and underwent abdominal tumor resection less frequently (68.5% vs. 84.4%, <it>P </it>< 0.001). Of 11,725 patients with abdominal tumor resection (anterior resection [AR], abdominoperineal excision [APE], and Hartmann's procedure [HA]), 37.4% were ≥75 years. Curative surgery was registered for 85.0% of patients ≥ 75 years and for 83.9% of patients < 75 years, <it>P </it>= 0.11. Choice of abdominal operation differed significantly between the two age groups for both curative and non-curative surgery, The frequency of APE was similar in both age groups (29.5% vs. 28.6%), but patients ≥75 years were more likely to have HA (16.9% vs. 4.9%) and less likely to have preoperative radiotherapy (34.3vs. 67.2%, <it>P </it>< 0.001). The relative survival rate at five years for all patients treated with curative intent was 73% (70–75%) for patients ≥75 years and 78% (77–79%) for patients < 75 years of age. Local recurrence rate was 9% (8–11%) for older and 8% (7–9%) for younger patients.</p> <p>Conclusion</p> <p>Treatment of rectal cancer is influenced by patient's age. Future studies should include younger and older patients alike to reveal whether or not age-related differences are purposive. Local recurrence following surgery for low tumors and quality of life aspects deserve particular attention.</p
Comparative Analysis on Property Improvement Using Fourier Transform Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR) (<sup>1</sup>H and <sup>13</sup>C) Spectra of Various Biodiesel Blended Fuels
The ever-increasing demand for energy has accelerated the research and development of renewable energy sources, which can eventually decrease the dependence on fossil fuel reserve. Biodiesel, a renewable energy source, has received considerable attention as an alternative fuel for the last few decades. In this study, biodiesels produced from two feedstocks were analyzed with a fatty acid methyl ester (FAME) composition, Fourier transform infrared (FT-IR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy (1H and 13C), in order to improve their physicochemical properties and determine the relationships among them. Here, the physicochemical properties of biodiesels produced from C. nucifera, and P. pinnata oils and their 5%, 10%, 20%, and 30% (by volume) blends were compared with pure diesel (B0), according to ASTM D6751 standards. All of the biodiesels and their blends satisfied the conditions to be an alternative fuel, compared to diesel but pure C. nucifera biodiesel, and their blends yielded more property improvement through their physicochemical property analysis and had the lowest carbon residue content. FAME composition, FT-IR and NMR spectra analysis were used to show the better properties of C. nucifera biodiesel and its blends through high ester content, transmittance, and conversion rate, respectively, than P. pinnata biodiesel and thus can be considered for commercial use in diesel engines
An overview on comparative engine performance and emission characteristics of different techniques involved in diesel engine as dual-fuel engine operation
Abatement of pollutant emissions from transport sector is one of the major concerns throughout the globe. One of the main technical challenges for transportation sector is to reduce pollutant emissions from diesel engine and to meet satisfactory engine performance, simultaneously. Different technical changes have been introduced in diesel engine to apply alternative biofuels to reduce pollutant emissions. Blend, fumigation, and emulsion are three different dual fuel engine operation techniques, which have been introduced in diesel engine for biofuel application. In the blend mode, biofuel and diesel are mixed in desired proportions before injecting into cylinder, whereas in fumigation mode, biofuel is injected into intake manifold to mix with the intake fresh air. Emulsion is a process wherein two immiscible substances are mixed together. This study provides a comprehensive review on these three techniques of biofuel injection and their comparative effects on the engine performance and emissions. From these studies, it is found that the effects on engine performance and emission mostly depend on biofuel properties. Increase in break specific fuel consumption (BSFC) is common in each method due to the lower calorific value of biofuels. Brake thermal efficiency (BTE) decreases in blend and fumigation modes, but increases in emulsion mode. Nitrogen oxides (NOx) emissions decrease in fumigation and emulsion modes, but increase in blend mode. Carbon monoxide (CO) and Hydro carbon (HC) emissions increase in fumigation and emulsion modes, but decrease in blend mode. Particulate Matter (PM) emission decreases in all three modes
A public survey on knowledge, awareness, attitude and willingness to pay for WEEE management: Case study in Bangladesh
This article is a first, limited attempt made to understand public knowledge, awareness, attitude and willingness to pay (WTP) in WEEE management in the context of Bangladesh, with a particular focus on the level of awareness, knowledge on WEEE, the reasons of discarding, priority choice, and disposal method. The purpose of this paper is to provide scientific knowledge basis promoting a policy agenda by assessing current WEEE management trend among households. Survey data has been collected by distributing questionnaires randomly in 7 residential areas in Dhaka, and interviewing 400 households. This study found a very limited knowledge on WEEE among households (i.e. only 9%). Competitive price, warranty period, brands and installment facilities are found important economic factors during the new purchase of electronic products. The actual life cycle of mobile phone, personal computers and television sets varies from 2 to 6 years. With the presence of informal sector WEEE collection and recycling, this study found that 30% of the households were selling WEEE items to scrap collectors for economic benefits. More than 20% of the respondents have thrown WEEE with household waste. Only 5–10% of the respondents are willing to pay for any new WEEE management system. Enacting effective regulations, developing national WEEE inventory database, environmental awareness building through education and stakeholders participation in creating economic value chain; are suggested through this study. This research is one of a kind in investigating the attitudes of the households of a developing nation towards WEEE management and will show the pattern of WEEE generation, disposal and management practice in the most densely populated city in the world, i.e., Dhaka, Bangladesh. Results found from this research are expected to create a primary basis for encouraging scientific discussion and understanding the situation at policy level in Bangladesh and will also pave the way for a successful WEEE management policy making in any similar social and economic conditions
Influence of poly(methyl acrylate) additive on cold flow properties of coconut biodiesel blends and exhaust gas emissions
Biodiesel comprises fatty acid esters and is used as an alternative fuel for diesel engines. However, biodiesel has poor cold flow properties (i.e., CP, CFPP and PP) than mineral diesel fuel. This study aims to reduce the PP, CFPP and CP of coconut biodiesel (CB) blends using poly(methyl acrylate) (PMA) additives and investigate their effects on single-cylinder four-stroke diesel engine performance and exhaust gas emission. DSC and TGA were used to observe crystal behavior and thermal stability of the biodiesel fuel blends. Engine performance and emission were analyzed by Dynomax-2000 software and gas analyzer, respectively. Results showed that 20% of CB blended with diesel and 0.03Â wt% of PMA showed significant improvement in the PP, CFPP and CP. Other properties of B20 with additives met the requirements of ASTM D6751. The BSFC of B20 with PMA was reduced by 3.247%, whereas the BTE was increased by 2.16%, compared with those of B20. Burning B20 with PMA increased the NO emission by 2.15%, whereas HC, CO and smoke emissions were 19.81%, 13.35% and 3.93% lower than those of B20, respectively. Therefore, CB20 blend with 0.03Â wt% PMA can be used as an alternative fuel in cold regions without compromising fuel quality
Evaluating combustion, performance and emission characteristics of Millettia pinnata and Croton megalocarpus biodiesel blends in a diesel engine
Biodiesel from non-edible vegetable oil is considered as a monetarily doable source among the conceivable sources. It can be used as a replacement of the fossil diesel without any modification of engine design. In this study, “Millettia pinnata" (MP) which is known as Karanja and “Croton megalocarpus” (CM), non-edible biodiesel feedstock sources used for biodiesel production. 20% (v/v) of each M. pinnata (MP20) and C. megalocarpus (CM20) and their combined blends were evaluated in a single-cylinder diesel engine with variable load and speed condition in the context of performance, combustion and emission characteristics. For speed test condition, MP20 and CM20 reduced the brake power by 3.70% and 0.53%, brake thermal efficiency by 3.36% and 1.41%, carbon dioxide emission by 18.46% and 6.20%, hydrocarbon emission by 9.00% and 2.89% respectively compared to neat diesel but increased the brake specific fuel consumption by 7.63% and 4.64%, NOX emission by 17.15% and 8.16%, respectively. Beyond diesel, a mixture of 5% MP and 15% CM biodiesel with 80% diesel (MP5CM15) provides higher in-cylinder peak pressure (77.44 bar), better heat release rate (39.26 J/°CA), shorter ignition delay and combustion duration. Thus MP5CM15 found to be a substitutable alternative to neat diesel except for NOX emission
Analysis of thermal stability and lubrication characteristics of: Millettia pinnata oil
Lubricants are mostly used to reduce the friction and wear between sliding and metal contact surfaces, allowing them to move smoothly over each other. Nowadays, due to the increase in oil prices and reduction of oil reserves, it is necessary to replace mineral oil, which will also protect the environment from hazards caused by these oils. It is essential to find an alternative oil for the replacement of mineral-oil-based lubricants, and vegetable oil already meets the necessary requirements. Vegetable-oil-based biolubricants are non-toxic, biodegradable, renewable and have a good lubricating performance compared to mineral-oil-based lubricants. This study analyzes the thermal stability and lubricating characteristics of different types of vegetable oil. The friction and wear characteristics of the oils were investigated using a four-ball tester, according to ASTM method 4172. Millettia pinnata oil has good oxidation stability due to the presence of higher percentages of oleic acid in its fatty acid composition. Millettia pinnata oil also shows a higher kinematic viscosity. Rice bran oil shows a higher viscosity index than other oils, and it is better for boundary lubrication. In thermogravimetric analysis, it was found that Millettia pinnata oil remains thermally stable at 391 °C. Millettia pinnata oil showed a lower coefficient of friction and rice bran oil showed a lower wear scar diameter compared to other vegetable oils and lube oils. A lower wear scar surface area was found with rice bran oil compared to other vegetable and commercial oils. Therefore, due to a better lubricating performance, Millettia pinnata oil has great potential to be used as a lubricating oil in industrial and automotive applications