Assessment of the impact of water parameters on the flow rate of ceramic pot filters in a long-term experiment

2015 ◽  
Vol 15 (6) ◽  
pp. 1425-1432 ◽  
Author(s):  
C. Salvinelli ◽  
A. C. Elmore

Poor water quality is a major contributing factor to disease in developing countries. Silver-coated ceramic pot filters (CPFs) are a relatively common form of household water treatment system (HWTS) representing an effective and sustainable technology for poor communities. Water production seems to be the major limiting factor of the CPF's lifetime and sustainability since low flow rates do not produce an adequate daily volume of treated water. This paper describes a long-term study of CPF flow rates under controlled conditions using three different water sources. The relationship between water characteristics and flow rate was assessed with the intent of identifying the principal parameters that impact CPF water production. The study concluded that turbidity seems to be the principal indicator in determining CPF lifetime in terms of quantity of treated water. There is no evidence that biological activity also contributes to premature failure of CPFs and the data did not indicate that chemical precipitation is responsible for the filter clogging. Manufacturers commonly conduct initial flow rate tests using clear water as a measure of quality assurance. However, the relationship between initial flow rate and average flow rate during the lifetime of the CPF should be further studied.

Parasitology ◽  
2015 ◽  
Vol 142 (8) ◽  
pp. 1033-1043 ◽  
Author(s):  
M. ZYLBERBERG ◽  
E. P. DERRYBERRY ◽  
C. W. BREUNER ◽  
E. A. MACDOUGALL-SHACKLETON ◽  
J. M. CORNELIUS ◽  
...  

SUMMARYThe impact of haematozoan infection on host fitness has received substantial attention since Hamilton and Zuk posited that parasites are important drivers of sexual selection. However, short-term studies testing the assumption that these parasites consistently reduce host fitness in the wild have produced contradictory results. To address this complex issue, we conducted a long-term study examining the relationship between naturally occurring infection withHaemoproteusandPlasmodium, and lifetime reproductive success and survival of Mountain White-crowned Sparrows. Specifically, we tested the hypothesis that birds infected with haematozoan parasites have reduced survival (as determined by overwinter return rates) and reproductive success. Contrary to expectation, there was no relationship betweenHaemoproteusandPlasmodiuminfection and reproduction or survival in males, nor was there a relationship betweenPlasmodiuminfection and reproduction in females. Interestingly,Haemoproteus-infected females had significantly higher overwinter return rates and these females fledged more than twice as many chicks during their lifetimes as did uninfected females. We discuss the impact of parasitic infections on host fitness in light of these findings and suggest that, in the case of less virulent pathogens, investment in excessive immune defence may decrease lifetime reproduction.


2016 ◽  
pp. 59-70
Author(s):  
Ninh Le Khuong ◽  
Nghiem Le Tan ◽  
Tho Huynh Huu

This paper aims to detect the impact of firm managers’ risk attitude on the relationship between the degree of output market uncertainty and firm investment. The findings show that there is a negative relationship between these two aspects for risk-averse managers while there is a positive relationship for risk-loving ones, since they have different utility functions. Based on the findings, this paper proposes recommendations for firm managers to take into account when making investment decisions and long-term business strategies as well.


Author(s):  
Pham Thu Huong ◽  
Jacob Cherian ◽  
Nguyen Thi Hien ◽  
Muhammad Safdar Sial ◽  
Sarminah Samad ◽  
...  

The present study aims to determine the impact of green innovation (GI) on the overall performance of an organization while keeping the variable of environmental management (EM) as a moderator. We used a dataset consisting of four data years, from 2014 to 2017, of A-share companies listed on the Shanghai Stock Exchange (SSE). The concept of green innovation refers to the use of advancements in technology that enable savings in energy, along with the recycling of waste material. When advanced technology is utilized in the production process, the products are referred to as green products and the whole process of adopting such technologies and product design is referred to as “Corporate Environmental Management”. Such innovations improve the overall financial performance of companies as it enables them to improve their social image by reducing their carbon footprint and ensures their long-term sustainability. The main issue is the limited focus and attention given to the topic, from the perspective of companies. This research focuses on the impact of green innovation and the importance of environmental management for the sustainability of companies. Our findings suggest that the relationship between green innovation and the performance of the company is positive and verifies the existence of moderating effects of environmental management on the relationship between green innovation and firm performance. Implications are given to academia and practitioners.


2021 ◽  
Vol 4 (7) ◽  
pp. 4-19
Author(s):  
Akmal Baltayevich Allakuliev ◽  

The article examines the interaction of the country's GDP with the state budget in the short and long term, the impact of the macro-fiscal mechanism on the country's economic growth on the example of Uzbekistan.The aim of the study is to identify dynamic correlations between the country's state budget expenditures and the economic growth of the macro-fiscal mechanism in the short and long term, as well as to analyze the approximation or rate of return of GDP and the state budget to equilibrium during various macroeconomic shocks. and hesitation.The scientific novelties of the research are:


1999 ◽  
Vol 14 (4) ◽  
pp. 41-46 ◽  
Author(s):  
Andrew J. Macnab ◽  
Lark Susak ◽  
Faith A. Gagnon ◽  
Janet Alred ◽  
Charles Sun

AbstractIntroduction:Pulse-oximetry has proven clinical value in Emergency Departments and Intensive Care Units. In the prehospital environment, oxygen is given routinely in many situations. It was hypothesized that the use of pulse oximeters in the prehospital setting would provide a measurable cost-benefit by reducing the amount of oxygen used.Methods:This was a prospective study conducted at 12 ambulance stations (average transport times >20 minutes). Standard care protocols and paramedic assessments were used to determine which patients received oxygen and the initial flow rate used. Pulse-oximetry measurements (oxygen-saturation measured by pulse oximetry) were then taken. If oxygen-saturation measured by pulse oximetry fell below 92% or rose above 96% (except in patients with chest pain), oxygen (O2) flow rates were adjusted. Costs of oxygen use were calculated: volume that would have been used based on initial flow rate; and volume actually used based on actual flow rates and transport time.Methods:A total of 1,907 patients were recruited. Oximetry and complete data were obtained on 1,787 (94%). Of these, 1,329 (74%) received O2 by standard protocol: 389 (27.5%) had the O2 flow decreased; 52 had it discontinued. Eighty-seven patients (6%) not requiring O2 standard protocol were hypoxemic (oxygen-saturation measured by pulse oximetry < 92%) by oximetry, and 71 patients (5%) receiving oxygen required flow rate increases. Overall, O2 consumption was reduced by 26% resulting in a cost-savings of $0.20 / patient. Prehospital pulse-oximetry allows unncessary or excessive oxygen therapy to be avoided in up to 55% of patients transported by ambulance and can help to identify suboptimally oxygenated patients (11%).Conclusion:Rationalizing the O2 administration using pulse-oximetry reduced O2 consumption. Other health care savings likely would result from a reduced incidence of suboptimal oxygenation. Oxygen cost-saving justifies oximeter purchase for each ambulance annually where patient volume exceeds 1,750, less frequently for lower call volumes, or in those services where the mean transport time is less than the 23 minute average noted in this study.


2016 ◽  
Vol 31 (2) ◽  
pp. 312-324 ◽  
Author(s):  
Javier González-Benito ◽  
Gustavo Lannelongue ◽  
Luis Miguel Ferreira ◽  
Carmen Gonzalez-Zapatero

Purpose – The purpose of this paper is to analyse the relationship between the environmental management of purchases and firm performance. The authors examine the moderating role played by two variables: the establishment of long-term relationships with suppliers and the strategic integration of the purchasing function. Design/methodology/approach – The authors conduct an empirical study on a sample of 100 Portuguese firms. Findings – Evidence reveals that green purchasing management improves the performance of the purchasing function, although the impact is greater when the organisation forges lasting alliances with its suppliers. Originality/value – This paper contributes to the study of the consequences of introducing environmental practices into the purchasing function, especially with regards to the formation of a panel of sustainable suppliers. Specifically, this research provides evidence to show that the implementation of those practices has positive impacts on the operating performance of the purchasing function and that the said effect is greater when a firm establishes long-term relationships with its suppliers.


2019 ◽  
pp. 54-78
Author(s):  
Yaroslav Tsytsiura

The article presents the results of a long-term study of the features of the phytocenology of agrophytocenoses of oil radish using different methods for assessing their condition and studying the tactics of the plant vitality strategy. A comprehensive assessment was made of the effect of changes in row spacing, seeding rates and fertilizer rates on the formation of various plant morphotypes, the variability of morphological characters and the general characteristics of plant viability. Three idiotypes of the plant oil radish were identified in a vertical study of agrophytocenosis, on the basis of which a detailed analysis of the variability of each group and a statistical assessment of the reliability of its existence were carried out. The features of the morphological integration of each tier are analyzed and its impact on the formation of the overall field productivity is evaluated. Based on the modular and vitality grouping, the effectiveness and feasibility of combining various options for plant density and fertilizer in the range of 30-90 kg of active substance per 1 ha were evaluated. Conclusions are drawn about the desired model of agrophytocenosis of oil radish based on the characteristics of its vital tactics and the goals of its growing. Grouping was carried out according to a variety of morphological traits of plants in the population and the possibilities of applying the basic patterns of phytocenology in their application to radish oilseed plants were evaluated. Through the use of regression analysis, the influence of climatic conditions on the formation of various morphological types of plants and the nature of the relationship of plants of oil radish in cenoses of various densities against the background of various fertilizer options has been evaluated. The main promising areas for further research on the peculiarities of creating highly productive and highly adaptable agrophytocenoses of oil radish have been outlined.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Chisato Izumi ◽  
Shuichi Takahashi ◽  
Sumiyo Hashiwada ◽  
Koji Hanazawa ◽  
Jiro Sakamoto ◽  
...  

Atheromatous plaques of the aorta have been regarded as a potential source of emboli, but there are few reports about the frequency and prognosis of patients with thoracic aortic plaques and about the relationship between plaque morphology and prognosis, especially long-term follow-up data. The purpose of this study is to clarify the impact of aortic atheromatous plaque morphology on survival rate and the incidence of subsequent embolic event. We retrospectively investigated 1570 consecutive patients who underwent transesophageal echocardiography between 1991 and 2003. The presence of severe plaque (>5mm in thickness) in the thoracic aorta were examined. Survival rate and subsequent embolic event rate were compared between patients with severe plaque and 109 control patients. The control patients were selected from the patients who showed no or mild plaque and as they were matched for age, gender, and risk factors of atherosclerosis with the patients with severe aortic plaque. The relationship between aortic plaque morphology and prognosis was also estimated, according to the presence of ulceration, calcification, hypoechoic plaques, and mobile plaques. Mean follow-up period was 8.7 years. Among 1570 patients, severe aortic plaque was detected in 92 patients (5.9%). These 92 patients showed significantly low survival rate and high subsequent embolic event rate compared with control patients (8-year survival rate, 50% vs 87%, 8-year embolic event free rate, 57% vs 90%). The relative risk of death was significantly increased for ulceration (2.4, 95% CI;1.1–5.2) and the relative risk of embolic events was significantly increased for mobile plaques (2.2, 95% CI;1.1–5.1). In conclusion, aortic plaque > 5mm in thickness was a predictor of a low survival rate and a high embolic event rate. Among patients with aortic plaque >5mm in thickness, ulceration was a predictor of a low survival rate and mobile plaque was a predictor of a high embolic event rate.


1991 ◽  
Vol 70 (6) ◽  
pp. 2514-2521 ◽  
Author(s):  
A. Kaise ◽  
A. N. Freed ◽  
W. Mitzner

In the present study, we investigated the interaction between CO2 concentration and rate of delivered flow on peripheral airway resistance (Rp) in the intact canine lung. Dogs were anesthetized, intubated, paralyzed, and mechanically ventilated with room air to maintain end-tidal CO2 between 4.8 and 5.2%. Using a wedged bronchoscope technique, we measured Rp at functional residual capacity. The relationship between CO2 concentration and Rp was measured at flow rates of 100 and 400 ml/min with 5, 3, 2, 1, and 0% CO2 in air. Measurements were made at the end of a 3-min exposure to each gas. At low flow rates (100 ml/min) responses to hypocapnia were small, whereas at high flow rates (400 ml/min) responses were large. The PC50 (defined as the CO2 concentration required to produce a 50% increase in Rp above baseline Rp established on 5% CO2) at 400 ml/min (1.73%) was significantly larger than that at 100 ml/min (0.38%). We also directly measured the relationship between Rp and flow rate with 5% CO2 (normocapnia) or 1% CO2 (hypocapnia) delivered into the wedged segment. Increases in normocapnic flow caused small but significant decreases in Rp. In contrast, increases in hypocapnic flow from 100 to 400 ml/min caused a 108% increase in Rp. Thus the response to hypocapnia is augmented by increasing flow rate. This interaction can be explained by a simple model that considers the effect of local ventilation-perfusion ratio and gas mixing on the local CO2 concentration at the site of peripheral airway contraction.


Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 264 ◽  
Author(s):  
Yongbin Bao ◽  
Fei Wang ◽  
Siqin Tong ◽  
Li Na ◽  
Aru Han ◽  
...  

As the main defoliators of coniferous forests in Shandong Province, China, pine caterpillars (including Dendrolimus suffuscus suffuscus Lajonquiere, D. spectabilis Butler, and D. tabulaeformis Tsai et Liu) have caused substantial forest damage, adverse economic impacts, and losses of ecosystem resources. Therefore, elucidating the effects of drought on the outbreak of these pests is important for promoting forestry production and ecological reconstruction. Accordingly, the aim of the present study was to analyse the spatiotemporal variation of drought in Shandong Province, using the Standard Precipitation Index, and to investigate the impact of drought on the outbreak of pine caterpillar infestations. Future trends in drought and pine caterpillar populations were then estimated using the Hurst exponent. The results showed that: (1) Drought decreased gradually and showed a wetting trend from 1981 to 2012, with frequency decreasing on a decadal scale as follows: 1980s > 1990s > 2000s > 2010s; (2) The total area of pine caterpillar occurrence decreased strongly from 1992 to 2012; (3) Long-term or prolonged drought had a greater positive impact on pine caterpillar outbreak than short-term drought; (4) In the future, a greater portion of the province’s area will experience increased wetting conditions (57%) than increased drought (43%), and the area of pine caterpillar outbreak is estimated to decrease overall. These findings help elucidate the relationship between drought and pine caterpillar outbreak in Shandong Province and, hence, provide a basis for developing preventive measures and plans.


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