The need for interval appendicectomy (I.A) after successful conservative management of appendiceal mass has recently been questioned.Furthermore,emergency appendicectomy for appendiceal mass is increasingly performed ...The need for interval appendicectomy (I.A) after successful conservative management of appendiceal mass has recently been questioned.Furthermore,emergency appendicectomy for appendiceal mass is increasingly performed with equal success and safety to that performed in non-mass forming acute appendicitis.There is an increasing volume of evidence-although mostly retrospective-that if traditional conservative management is adopted,there is no need for routine I.A except for a small number of patients who continue to develop recurrent symptoms.On the other hand,the routine adoption of emergency laparoscopic appendicectomy (LA) in patients presenting with appendiceal mass obviates the need for a second admission and an operation for I.A with a considerable complication rate.It also abolishes misdiagnoses and deals promptly with any unexpected ileo-cecal pathology.Moreover,it may prove to be more cost-effective than conservative treatment even without I.A due to a much shorter hospital stay and a shorter period of intravenous antibiotic administration.If emergency LA is to become the standard of care for appendiceal mass,I.A will certainly become 'something' of the past.展开更多
India is having more than 500,000 villages of which about 85% have been electrified. But as per RGGVY （Rejiv Gandhi Grammen Vidyutikaran Yojana）, the rate of village electrification is much lower as household connec...India is having more than 500,000 villages of which about 85% have been electrified. But as per RGGVY （Rejiv Gandhi Grammen Vidyutikaran Yojana）, the rate of village electrification is much lower as household connectivity has been fairly low. The rest 15% villages and a larger proportion of households have to be electrified. Villages have been a major concern as cost of electrification is fairly high. The most favored alternative to any kind of users is generation of electricity from diesel generating sets and renewable sources of energy. But the capital cost of renewable energy equipments is fairly high. Gradually, there is a reduction in the prices of these systems due to availability of better technological options and they are becoming competitive to grid electricity. In this paper, an attempt has been made to calculate the cost of production of electricity from stand-alone, off-grid devices biomass gasifiers （both dual fuel and pure gas type） and compare with that of diesel generating sets by using the concept of LCC （life cycle costing） and Homer software. It is found that the cost of per unit electricity generation （kWh） has been always the lowest in comparison to diesel generating sets even if the price of biomass increases to some extent.展开更多
Mango fruit （Mangifera indica） is very rich in fibre and vitamin C which are the required nutrients for good health and easy digestion of food in human body system. However, the fruit is highly perishable in its nat...Mango fruit （Mangifera indica） is very rich in fibre and vitamin C which are the required nutrients for good health and easy digestion of food in human body system. However, the fruit is highly perishable in its natural state after harvest due to the chemical deterioration and environmental effects. Due to the perishable nature, abundant wastage during the production season and relative scarcity during the off season were recorded by farmers. Processing the fruit into the form that can easily be stored, preserved, packaged, transported or consumed is crucial to having the product all the year round. Besides, mango juice can be consumed freshly, processed into dry powder, mixed or blended with other juice to make fruit jams, or evaporated to concentrates. These products have a lot of potential in food and beverage industries for export and foreign exchange earnings. Therefore, a small scale machine to process mango fruits to high quality juice is highly essential to reduce the postharvest loss and then add value to the commodity. To achieve this purpose, an abrasion-macerating device （AMD） was designed, fabricated and tested for small scale mango juice extraction. Design considerations focused on the techno-economic status of the micro and small scale fruit juice processors who are the intended users of the machine. The major components of the machine included hopper, perforated drum, screw conveyor, juice outlet, waste outlet, frame, electric motor and motor stand. Other components included screw shaft, the juice collector, top cover and the transmission system. In operation, the screw conveyor conveys and presses the mango fruits against the perforated roughened drum. The abrasion/tearing process of the screw on the flesh of the fruit and further pressing against the drum squeeze enough juice out of the fruit. The juice extracted is drained through the perforated mesh of the juice channel into the juice outlet from where it is collected while the residual waste is collected at the waste outlet. The machine was tested using freshly harvested mango fruits and results obtained showed an average juice yield, extraction efficiency and extraction loss of 34,56%, 55.14% and 10.15%, respectively. These values of juice yield, extraction efficiency and low level of extraction loss indicate satisfactory performance of the machine. Powered by a 2.5 hp single-phase electric motor, the machine has a production cost of USD565 with the construction materials being locally available at affordable costs. A cottage mango juice extraction plant based on this technology can provide employment for at least two persons at the same time providing fresh juice at low costs and residual waste as an ingredient for livestock feed manufacturing.展开更多
The silicon wafer accounts nearly half of the photovoltaic module cost, and hence on this issue an important opportunity remains for further decreasing the cost of photovoltaics. It is well known that ribbon technolog...The silicon wafer accounts nearly half of the photovoltaic module cost, and hence on this issue an important opportunity remains for further decreasing the cost of photovoltaics. It is well known that ribbon technology has a large potential for costs reduction by avoiding kerr losses since no saw processes are used, preventing material losses up to 50% of the initial feedstock. On the other hand we ought to ask ourselves why we should use solid silicon feedstock, which has already undergone a crystallization process with high energy content to recrystallize it again in a crucible, spending even more energy, when we can go directly from the gaseous feedstock source to the final ribbon. The cost cutting strategy that supports the Silicon over Dust Substrate （SDS） technology, here presented, is based on the belief that ribbon technology and the silicon feedstock issue will play an important role on ＂wafer＂ cost reduction.展开更多
Due to high price of Straight Vegetable Oil （SVO） for bio-diesel production, the use of Waste Cooking Oil （WCO） will be cost effective. Furthermore, utilization of WCO will refrain waterways pollution and endanger...Due to high price of Straight Vegetable Oil （SVO） for bio-diesel production, the use of Waste Cooking Oil （WCO） will be cost effective. Furthermore, utilization of WCO will refrain waterways pollution and endanger ecosystem. In Malaysia, more than 50-tone of WCO from various sources was produced every day. This study evaluates combustion performance and exhaust emission characteristics of several WCOs with different sources. Modification on fuel properties has been done to improve the combustion and exhaust emission of using WCO as diesel fuel. Regular diesel fuel also has been used for comparison in the test. A 0.6 liter, single-cylinder, air-cooled direct injection diesel engine was used to perform this experiment. Experiment was done at variable engine loads at constant speed.展开更多
Energy requirements for tertiary educational purpose is burgeoning, a reflection of its criticality to human asset formation and to use self auto-generation by petrol or diesel generators as the energy supply source i...Energy requirements for tertiary educational purpose is burgeoning, a reflection of its criticality to human asset formation and to use self auto-generation by petrol or diesel generators as the energy supply source is an unsustainable practice. The situation is worrisome in view of the noise pollution and nuisance that constitutes to the learning environment. This paper, therefore, determines the quantity of self generated energy supply, its intensity, the associated CO2 emissions and their possible implications for human capital development. A survey of generating sets was conducted using the University of Nigeria Nsukka as a representative of Nigerian universities. A walk-through-approach was adopted in gathering data and two metrics-life cycle cost and cost of electricity from auto-generation were used to determine the economic implications of the self generation. The results show that self auto-generation contributed installed energy capacity of amount 19 MVA, 20 MVA, 34 MVA, 11 MVA and 22 MVA to run human capital development activities, respectively for academic sessions from July 2006 to November 2010. The study helps us understand that reforms in educational sector are not effective as long as energy insecurity is a dominant factor.展开更多
This article classifies the seawater desalination technology into four types of hot method, membrane method, electric field method and solvent method. Electric field method and solvent method still remain experimental...This article classifies the seawater desalination technology into four types of hot method, membrane method, electric field method and solvent method. Electric field method and solvent method still remain experimental stage, while hot method and membrane method have been realized in commercialization but are difficult to be promoted. The problem lies in high water-producing cost. It is difficult for membrane method seawater desalination technology to reduce the water-producing cost. The heat utilization efficiency is not high for the current hot method seawater desalination technology and there is large amount of heat lost with the emission of concentrated seawater. The new hot method seawater desalination technology and new solar-powered seawater desalination technology can divide the seawater into fresh water and solid salt without any emission of concentrated seawater so that the heat utilization efficiency can reach theoretical limit to multiply reduce the water-producing cost. They will become the mainstream technology for seawater desalination and can totally eliminate the global water crisis.展开更多
The interaction between Hertwig＇s epithelial root sheath （HERS） and the adjacent mesenchyme is vitally important in mouse tooth root development. We previously generated odontoblast-specific Ctnnbl （encodingβ-cat...The interaction between Hertwig＇s epithelial root sheath （HERS） and the adjacent mesenchyme is vitally important in mouse tooth root development. We previously generated odontoblast-specific Ctnnbl （encodingβ-catenin） deletion mice, and demon- strated that odontoblast β-catenin signaling regulates odontoblast proliferation and differentiation. However, the role of odon- toblast β-catenin signaling in regulation of HERS behavior has not been fully investigated. Here, using the same odonto- blast-specific Ctnnbl deletion mice, we found that ablation of β-catenin signaling in odontoblasts led to aberrant HERS for- mation. Mechanistically, odontoblast-specific Ctnnbl deletion resulted in elevated bone morphogenetic protein 7 （Bmp7） ex- pression and reduced expression of noggin andfollistatin, both of which encode extracellular inhibitors of BMPs. Furthermore, the levels of phosphorylated Smadl/5/8 were increased in HERS cells. In vitro tissue culture confirmed that BMP7 treatment disrupted the HERS structure. Taken together, we demonstrated that odontoblast f3-catenin signaling may act through regula- tion of BMP signaling to maintain the integrity of HERS cells.展开更多
文摘The need for interval appendicectomy (I.A) after successful conservative management of appendiceal mass has recently been questioned.Furthermore,emergency appendicectomy for appendiceal mass is increasingly performed with equal success and safety to that performed in non-mass forming acute appendicitis.There is an increasing volume of evidence-although mostly retrospective-that if traditional conservative management is adopted,there is no need for routine I.A except for a small number of patients who continue to develop recurrent symptoms.On the other hand,the routine adoption of emergency laparoscopic appendicectomy (LA) in patients presenting with appendiceal mass obviates the need for a second admission and an operation for I.A with a considerable complication rate.It also abolishes misdiagnoses and deals promptly with any unexpected ileo-cecal pathology.Moreover,it may prove to be more cost-effective than conservative treatment even without I.A due to a much shorter hospital stay and a shorter period of intravenous antibiotic administration.If emergency LA is to become the standard of care for appendiceal mass,I.A will certainly become 'something' of the past.
文摘India is having more than 500,000 villages of which about 85% have been electrified. But as per RGGVY （Rejiv Gandhi Grammen Vidyutikaran Yojana）, the rate of village electrification is much lower as household connectivity has been fairly low. The rest 15% villages and a larger proportion of households have to be electrified. Villages have been a major concern as cost of electrification is fairly high. The most favored alternative to any kind of users is generation of electricity from diesel generating sets and renewable sources of energy. But the capital cost of renewable energy equipments is fairly high. Gradually, there is a reduction in the prices of these systems due to availability of better technological options and they are becoming competitive to grid electricity. In this paper, an attempt has been made to calculate the cost of production of electricity from stand-alone, off-grid devices biomass gasifiers （both dual fuel and pure gas type） and compare with that of diesel generating sets by using the concept of LCC （life cycle costing） and Homer software. It is found that the cost of per unit electricity generation （kWh） has been always the lowest in comparison to diesel generating sets even if the price of biomass increases to some extent.
文摘Mango fruit （Mangifera indica） is very rich in fibre and vitamin C which are the required nutrients for good health and easy digestion of food in human body system. However, the fruit is highly perishable in its natural state after harvest due to the chemical deterioration and environmental effects. Due to the perishable nature, abundant wastage during the production season and relative scarcity during the off season were recorded by farmers. Processing the fruit into the form that can easily be stored, preserved, packaged, transported or consumed is crucial to having the product all the year round. Besides, mango juice can be consumed freshly, processed into dry powder, mixed or blended with other juice to make fruit jams, or evaporated to concentrates. These products have a lot of potential in food and beverage industries for export and foreign exchange earnings. Therefore, a small scale machine to process mango fruits to high quality juice is highly essential to reduce the postharvest loss and then add value to the commodity. To achieve this purpose, an abrasion-macerating device （AMD） was designed, fabricated and tested for small scale mango juice extraction. Design considerations focused on the techno-economic status of the micro and small scale fruit juice processors who are the intended users of the machine. The major components of the machine included hopper, perforated drum, screw conveyor, juice outlet, waste outlet, frame, electric motor and motor stand. Other components included screw shaft, the juice collector, top cover and the transmission system. In operation, the screw conveyor conveys and presses the mango fruits against the perforated roughened drum. The abrasion/tearing process of the screw on the flesh of the fruit and further pressing against the drum squeeze enough juice out of the fruit. The juice extracted is drained through the perforated mesh of the juice channel into the juice outlet from where it is collected while the residual waste is collected at the waste outlet. The machine was tested using freshly harvested mango fruits and results obtained showed an average juice yield, extraction efficiency and extraction loss of 34,56%, 55.14% and 10.15%, respectively. These values of juice yield, extraction efficiency and low level of extraction loss indicate satisfactory performance of the machine. Powered by a 2.5 hp single-phase electric motor, the machine has a production cost of USD565 with the construction materials being locally available at affordable costs. A cottage mango juice extraction plant based on this technology can provide employment for at least two persons at the same time providing fresh juice at low costs and residual waste as an ingredient for livestock feed manufacturing.
文摘The silicon wafer accounts nearly half of the photovoltaic module cost, and hence on this issue an important opportunity remains for further decreasing the cost of photovoltaics. It is well known that ribbon technology has a large potential for costs reduction by avoiding kerr losses since no saw processes are used, preventing material losses up to 50% of the initial feedstock. On the other hand we ought to ask ourselves why we should use solid silicon feedstock, which has already undergone a crystallization process with high energy content to recrystallize it again in a crucible, spending even more energy, when we can go directly from the gaseous feedstock source to the final ribbon. The cost cutting strategy that supports the Silicon over Dust Substrate （SDS） technology, here presented, is based on the belief that ribbon technology and the silicon feedstock issue will play an important role on ＂wafer＂ cost reduction.
文摘Due to high price of Straight Vegetable Oil （SVO） for bio-diesel production, the use of Waste Cooking Oil （WCO） will be cost effective. Furthermore, utilization of WCO will refrain waterways pollution and endanger ecosystem. In Malaysia, more than 50-tone of WCO from various sources was produced every day. This study evaluates combustion performance and exhaust emission characteristics of several WCOs with different sources. Modification on fuel properties has been done to improve the combustion and exhaust emission of using WCO as diesel fuel. Regular diesel fuel also has been used for comparison in the test. A 0.6 liter, single-cylinder, air-cooled direct injection diesel engine was used to perform this experiment. Experiment was done at variable engine loads at constant speed.
文摘Energy requirements for tertiary educational purpose is burgeoning, a reflection of its criticality to human asset formation and to use self auto-generation by petrol or diesel generators as the energy supply source is an unsustainable practice. The situation is worrisome in view of the noise pollution and nuisance that constitutes to the learning environment. This paper, therefore, determines the quantity of self generated energy supply, its intensity, the associated CO2 emissions and their possible implications for human capital development. A survey of generating sets was conducted using the University of Nigeria Nsukka as a representative of Nigerian universities. A walk-through-approach was adopted in gathering data and two metrics-life cycle cost and cost of electricity from auto-generation were used to determine the economic implications of the self generation. The results show that self auto-generation contributed installed energy capacity of amount 19 MVA, 20 MVA, 34 MVA, 11 MVA and 22 MVA to run human capital development activities, respectively for academic sessions from July 2006 to November 2010. The study helps us understand that reforms in educational sector are not effective as long as energy insecurity is a dominant factor.
文摘This article classifies the seawater desalination technology into four types of hot method, membrane method, electric field method and solvent method. Electric field method and solvent method still remain experimental stage, while hot method and membrane method have been realized in commercialization but are difficult to be promoted. The problem lies in high water-producing cost. It is difficult for membrane method seawater desalination technology to reduce the water-producing cost. The heat utilization efficiency is not high for the current hot method seawater desalination technology and there is large amount of heat lost with the emission of concentrated seawater. The new hot method seawater desalination technology and new solar-powered seawater desalination technology can divide the seawater into fresh water and solid salt without any emission of concentrated seawater so that the heat utilization efficiency can reach theoretical limit to multiply reduce the water-producing cost. They will become the mainstream technology for seawater desalination and can totally eliminate the global water crisis.
基金supported by grants from the State Key Program of the National Natural Science Foundation of China(81030018)the National Basic Research Program of China(2012CB966904)the National Natural Science Foundation of China(30900863,81241062)
文摘The interaction between Hertwig＇s epithelial root sheath （HERS） and the adjacent mesenchyme is vitally important in mouse tooth root development. We previously generated odontoblast-specific Ctnnbl （encodingβ-catenin） deletion mice, and demon- strated that odontoblast β-catenin signaling regulates odontoblast proliferation and differentiation. However, the role of odon- toblast β-catenin signaling in regulation of HERS behavior has not been fully investigated. Here, using the same odonto- blast-specific Ctnnbl deletion mice, we found that ablation of β-catenin signaling in odontoblasts led to aberrant HERS for- mation. Mechanistically, odontoblast-specific Ctnnbl deletion resulted in elevated bone morphogenetic protein 7 （Bmp7） ex- pression and reduced expression of noggin andfollistatin, both of which encode extracellular inhibitors of BMPs. Furthermore, the levels of phosphorylated Smadl/5/8 were increased in HERS cells. In vitro tissue culture confirmed that BMP7 treatment disrupted the HERS structure. Taken together, we demonstrated that odontoblast f3-catenin signaling may act through regula- tion of BMP signaling to maintain the integrity of HERS cells.
