The efficiency of pilot plant stabilization pond treatment of wastewater

A pilot plant stabilization pond (SP) using Jerusalem wastewater primary effluent, was constructed to study the effect of hydraulic characteristics on treatment system performance. The system consists of six ponds: the first, 3 m3, and the remainder 1 m3 each. Two longitudinal baffles were installed in ponds 1 and 5, and two cross-sectional baffles in ponds 2 to 4. Pond 6 was without baffles. Two runs were made, using two theoretical detention times (TDT): 11 and 33 days. In each run, rhodamine water tracer (RWT) studies were conducted, biological oxygen demand (BOD) was determined, and physico-chemical and microbiological tests were carried out. According to the tracer study, the first pond had a flow pattern similar to an idealized completely mixed pattern. In the remaining series of ponds, the flow was similar to that of an idealized plug flow pattern, and with more efficient usage of pond volume as compared with that of a single SP. Thermal stratification occurred during the day in ponds with or without longitudinal baffles, causing hydraulic failures. However, ponds with cross-sectional baffles showed no thermal stratification, had higher microbial decay rates, and displayed improved treatment efficiency. The tested microorganisms at the exit of pond 6 were reduced by up to 1.8 logs after 11 days of TDT, and by 3.3 to 5.2 logs after 33 days of TDT. BOD was reduced by 79 and 93% respectively. In the baffled SP pilot plant, 27 days of TDT were required to achieve the WHO guidelines of 1000 F. coliforms/100 ml wastewater effluent for unrestricted irrigation.     

正畸治疗效果评价标准的研究现状

随着采用正畸治疗纠正牙颌面畸形的人数日渐增多,治疗方案多样且个性化,加之生物-心理-社会医学模式兴起,使越来越多的人关注社会心理因素对正畸结果的影响,因此对正畸治疗临床质量的把控尤为重要。本文将从功能与美学、社会心理2个方面对正畸治疗效果评价标准的研究现状进行综述。     

Numerical methods for the evaluation of individual bioequivalence criteria

The evaluation of individual bioequivalence (IBE) by bootstrap resampling using common statistical software, for example SAS, is extremely time consuming. In this article, an estimation procedure that can be implemented in a high level language with the same degree of accuracy as SAS is described. The necessary parameter estimating equations under both least square (LSE) and restricted maximum likelihood (REML) methods are given. The algorithms used to numerically compute these values are outlined and tested, in FORTRAN, on several simulated data sets and shown to reproduce SAS results with at least 10(-3) precision. More importantly, the REML bootstrap algorithm reduces the time taken in SAS by a factor of 20. Secondary results indicate that LSE and REML parameter estimates are similar for mild unbalancedness. PROC MIXED, with unstructured (UN) and compound symmetry heterogeneous (CSH) variance structures give the same results except when the subject-by-treatment interaction variance, sigma(2)(D), is 0 in which case CSH significantly overestimates sigma(2)(D) and underestimates the within-treatment variances. It is concluded that bootstrap evaluation of IBE is efficiently done using either the LSE or REML algorithm in FORTRAN.     

Performance criteria for evaluation of medical teachers

Evaluation of medical teachers must be related systematically to individualized objectives that are derived from a specific statement of the goals of the medical school. This paper describes the application of management-by-objectives to the problem of assessment of performance of medical teachers. The approach provides for the identification of significant objectives and rates performance in relation to achievement of outcomes rather than of activities.     

煤渣对废水中氨氮吸附效果的影响因素研究

目的 研究煤渣吸附废水中氨氮效果的影响因素.方法 采用静态试验方法,测定在不同反应接触时间(2～24h)、煤渣的投加量(2～20 g)、水样中氨氮的初始浓度(1～30 mg/L)以及反应温度(20～40℃)下煤渣对模拟水样中氨氮的吸附效果.结果 在最佳条件(即吸附时间为12h,煤渣投入量为10 g,水样中氨氮的初始浓度为20 mg/L,反应温度为25℃)下,煤渣对模拟水样中氨氮的去除率为45％.结论 煤渣可较好地去除废水中的氨氮.     

Prioritisation criteria for the selection of new diagnostic technologies for evaluation

Background  

Currently there is no framework for those involved in the identification, evaluation and prioritisation of new diagnostic technologies. Therefore we aimed to develop prioritisation criteria for the assessment of new diagnostic technologies, by gaining international consensus on not only which criteria should be used, but also their relative importance.     

Quantitative criteria for the evaluation of congenital chromatic vision disorders

The minimum angular size of a color stimulus required for its discrimination has been ascertained to be a quantitative criterion for evaluating the form and degree of congenital chromatic visual diseases. Unlike individuals with normal color perception who distinguish all basic and intermediate colors despite their saturation, anomalous trichromats discriminate more saturated colors with larger angular sizes of stimuli than those with normal color perception. Mild and moderate anomalous trichromats do not discriminate lowly saturated colors or for this they require the angular sizes tens of times greater those for normal trichromats. Persons with severe chromatic visual diseases (Type A) do not distinguish moderately saturated colors either. On recognizing the color of test objects, anomalous trichomats make the most mistakes in perceiving the green and yellow colors, the fewest mistakes in perceiving the red color. The minimum angular sizes required to distinguish colors, the percent of errors in their discrimination, and the range of vision of safety signs depend on the form and degree of congenital chromatic diseases. This makes it necessary to apply a differential approach to providing jobs that require rapid and accurate color discrimination in persons with the protanomalous forms of chromatic pathology.     

CT照片质量临床评价标准的研究

CT照片的质量评价,通常是采用主观和经验的方法,在具体操作中有一定的困难。本文试图采用量化或半量化的方法,以期获得相对客观的评价标准。作者随机从各等级CT机型中,每一等级机型选择4－5家医院－共13家医院的颅脑;胸部、上腹部及腰椎4个部位的平扫CT片共400份,统一规定扫描方式与扫描参数。经过反复测算,将各部位的评审参数分解为解剖结构的显示、CT值测量、CT机伪影以及图像观感4个方面。同时又细分了有关的评审参数,并且根据各参数在图像质量中的重要性采取加以不同“权重”的方法。参数指标的评分又细分为AA到DD6级,也通过多次测算分别赋值。最后根据每张照片所获得的总分评定为甲、乙、丙及不及格4个等级,据此制定了“CT照片临床应用评审表”。评审结果基本符合北京市医院的实际情况,即北京市医院CT照片质量总体上是比较好的。各解剖部位的甲级片为31．1％（胸部）－56．4％（腹部）,丙级片为7．9％（颅脑）－15．6％（胸部）,不及格片仅占4．4％（颅脑）。本文还讨论了各评定参数的必要性与评审中的问题。通过与年轻医师的双盲评审,认为本文（胸部）,不及格片仅占4．4％（颅脑）。本文还讨论了各评审参数的必要性与评审中的问题。通过与年轻医师的双盲评审,认为本文提出的经过量化的评审标准对CT照片的评审很有用处,但乃有一定的主观性,评审工作必须由有经验的医师进行。     

Determination of wastewater LC50 of the different process stages of the textile industry

Textile plants are very important sources of toxic discharges. The purpose of the research described in this paper was to use bioassays with daphnids to determine the LC50 values of textile wastewater samples taken from different stages of the finishing textile industry. Toxicity due to dyeing, chlorination, and the absence of adequate physicochemical conditions for daphnid survival were considered. Wastewater samples corresponding to each process stage were collected at five finishing textile industries and assayed according to previously published procedures. The sensitivity of daphnids to chemicals was assayed using sodium dodecyl sulfate and was similar to other reports (14.6+/-6.8 vs 14.5+/-2.3 mg/L). All effluents from the five company samples were toxic in terms of LC50 and exhibited very high toxicity with acute toxicity unit (ATU) levels between 2.2 and 960, indicating that the five textile industries produced toxic water. The sensory characteristics indicated that the dyes contributed to overall sample toxicity at all process stages. The most toxic contaminant seemed to be ClO- at levels between 0.2 and 6.8 mg/L, suggesting that further research is needed on the economic costs of stage-by-stage and total effluent treatments.     

Quality of ambulatory care for the elderly: formulating evaluation criteria

Efforts to assess the quality of ambulatory care services provided to Medicare beneficiaries cannot meaningfully proceed unless a concerted effort is made to develop criteria and standards for ambulatory care quality assessment that reflect the specific characteristics and needs of the elderly. In this article, we describe some of those characteristics and needs--such as physical and mental impairments and multiple coexisting conditions--and we show how they affect the care provided to the elderly and, therefore, the proper assessment of that care. We also outline an approach for the orderly development of the requisite criteria and standards.     

Quality of care and the patient: new criteria for evaluation

Quality in health care has two critical components: quality in practice and quality in perception. The first involves meeting your own or some other set of standards; the second, meeting your customers' expectations. Neither of these essentials will, by itself, carry a hospital far. This article examines the extent to which customer perception is important in understanding the concept of quality in health care.     

Markers for nutrition studies: review of criteria for the evaluation of markers

Introduction

Markers are important tools to assess the nutrition status and effects of nutrition interventions. There is currently insufficient consensus in nutrition sciences on how to evaluate markers, despite the need for properly evaluating them.

Objectives

To identify the criteria for the evaluation of markers related to nutrition, health and disease and to propose generic criteria for evaluation.

Method

The report on “Evaluation of Biomarker and Surrogate Endpoints in Chronic Disease” from the Institute of Medicine was the starting point for the literature search. Additionally, specific search strategies were developed for Pubmed.

Results

In nutrition, no set of criteria or systematic approach to evaluate markers is currently available. There is a reliance on the medical area where statistical methods have been developed to quantify the evaluation of markers. Even here, a systematic approach is lacking—markers are still evaluated on a case-by-case basis. The review of publications from the literature search resulted in a database with definitions, criteria for validity and the rationale behind the criteria. It was recognized that, in nutrition, a number of methodological aspects differ from medical research.

Conclusions

The following criteria were identified as essential elements in the evaluation of markers: (1) the marker has a causal biological link with the endpoint, (2) there is a significant association between marker and endpoint in the target population, (3) marker changes consistently with the endpoint, e.g., in response to an intervention, and (4) change in the marker explains a substantial proportion of the change in the endpoint in response to the intervention.     

Treatment of textile dyeing wastewater using UV/solar photofenton oxidation processes

Colour removal of effluent from textile dyeing and finishing industry is becoming important because of aesthetic as well as environmental concerns. Conventional treatment methods have several limitations. Hence emerging technologies like advanced oxidation processes which were based on generation of hydroxyl free radicals (OH) were investigated. In the present work, photofenton oxidation process was used to treat textile dyeing wastewater and the study was carried out at different Fenton molar ratio's (H2O2/Fe2+) like 25:1, 50:1, 75:1, 100:1. It was found that maximum decolourisation occurred at a fenton molar ration of 50:1 and pH 3. A maximum colour removal of 97% was achieved after a contact time of 30 minutes and 70% COD reduction was observed after a contact time of 60 minutes in UV photofenton oxidation process. Whereas 80% colour removal and 50-55% COD reduction was observed after a contact time of 2 hrs in solar photofenton oxidation process.     

A new method for visual efficiency evaluation

We made an octotype with a grey scale to be able to evaluate minimal visual changes. This instrument is very help full for detection of minimal functional worsening especially in maculopathies and neuritis.