Phase change material (PCM) is considered as one of the most effective thermal energy storage (TES) systems to balance energy supply and demand. A key challenge in designing efficient PCM-based TES systems lies in the enhancement of heat transmission during phase transition. This study numerically examines the privilege of employing twisted-fin arrays inside a shell-and-tube latent heat storage unit to improve the solidification performance. The presence of twisted fins contributes to the dominating role of heat conduction by their curved shapes, which restricts the role of natural convection but largely aids the overall heat-transfer process during solidification. The heat-discharge rate of twisted-fin configuration is increased by ∼14 and ∼55% compared to straight fin and no fin configurations—leading to a reduction in the solidification duration by ∼13 and ∼35%, respectively. The solidification front at various times has also been assessed through a detailed parametric study over the fin height, fin pitch number, and fin thickness. Over the range of values assumed, the fin height is the most dominant parameter – increasing the heat-retrieval rate from 10.0 to 11.4 W and decreasing the discharge time from above 3600 to 2880 s by varying the fin height from 2.5 to 7.5 mm.
Efficient and cost-effective drilling of directional wells necessitates the implementation of best drilling practices and advanced techniques to optimize drilling operations. Failure to adequately consider drilling risks can result in inefficient drilling operations and non-productive time (NPT). Although advanced drilling techniques may be expensive, they offer promising technical solutions for mitigating drilling risks. This paper aims to demonstrate the effectiveness of advanced drilling techniques in mitigating risks and improving drilling operations when compared to conventional drilling techniques. Specifically, the advanced drilling techniques employed in Buzurgan Oil Field, including vertical drilling with mud motor, managed pres
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The research was limited to those whom Imam Abu Dawood
described in his Sunan as weak, so this research does not include
narrators who carried descriptions indicating weakness such as
ignorance or others, nor does it include hadiths that the Imam
described as weak.
The number of narrators whom Imam Abu Dawood described as
weak has reached six narrators, and my methodology was to
mention the words of Imam Abu Dawood, then transfer the
sayings of other advanced scholars, as well as the sayings of
Imam Abu Dawood in his other books, if any, to show the extent
of compatibility between these sayings.
I have reached the following resul
... Show MoreThe clayey soils have the capability to swell and shrink with the variation in moisture content. Soil stabilization is a well-known technique, which is implemented to improve the geotechnical properties of soils. The massive quantities of waste materials are resulting from modern industry methods create disposal hazards in addition to environmental problems. The steel industry has a waste that can be used with low strength and weak engineering properties soils. This study is carried out to evaluate the effect of steel slag (SS) as a by-product of the geotechnical properties of clayey soil. A series of laboratory tests were conducted on natural and stabilized soils. SS was added by 0, 2.5, 5, 10, 15, and 20% to the soil.
... Show MoreEichhornia, or water hyacinth represents a serious threat to potable water basins. This problem is materialized majorly in consuming large amounts of water and dissolved Oxygen that is necessary for aquatic life, and minorly in hindering water streams. Even there are limited trials to overcome such pests, none of them presents an acceptable solution economically and logically. Chlorine is a well-known biocide and broadly used in water industry. It could give a possible method to fight such weed. To investigate that, concentration-time plot should be introduced similar to any other microorganisms; especially, bacteria in water. In this work, various doses of Chlorine along various time
The present study aims at assessing the status of heavy metals such as nickel, cadmium and lead to pollute some areas of Baghdad city. In this study the spectral absorption device and the program ArcGIS 10.2 will using. The soil samples were taken from five different locations in Baghdad, including Ameriya, Kadhimiya, Palestine Street, Jadiriyah and Taji for the 5cm depth layer on both sides of the road. This work on soil samples has been completed in two :phases 1 - Preparation of samples: For the purpose of converting solid material into a extract containing elements in the form of single ions can be estimated by the device 2-Determination of elements: Samples prepared to the device
Phenomena of an abnormal genitalia was among some specimens of Cicindela aulica Dej.
Collected from Iraq. The fore tarsi of male were asymmetrical having its basal three segments
dilated and clothed beneath with fine bristles as in normal male. While those of the right leg
were found simple as in normal females. Dissection of the genialia of these specimens
showed that they were of two types of both male and female structures.
The most important environmental constraints at the present time
is the accumulation of glass waste (transparent glass bottles). A lot of
experiments and research have been made on waste and recycling
glass to get use it as much as possible. This research using recycling
of locally waste colorless glass to turn them into raw materials as
alternative of certain percentages of cement to save the environment
from glass waste and reduce some of the disadvantages of cement
with conserving the mechanical and physical properties of concrete
made. A set of required samples were prepared for mechanical test
with different weight percentage of waste glass (2%, 4%, 5%, 6%,
8%, 10%, 15%, 20% and 25%). American standard
Background: Ambulatory peritoneal dialysis
introduced by Popvich et al (13) in 1978 , consists of a
four to five hours lavage of peritoneal cavity with 2000
ml of glucose solution .It remains a useful method for
treating patients with end stage renal failure till renal
transplantation becomes possible.
Objectives: The aim of the study is to evaluate the
value of cytological changes of mesothelial cells in
dialysate patients.
Methods: Within one year period, 32 cytological
peritoneal fluid samples were collected from patients
with end stage renal failure regardless of the underlying
causes, admitted to the dialyzing unit in Kadimya
Teaching Hospital. Smears were prepared and fixed in
95 % ethyl al
Background: The first and second choice for vascular access in patients with end stage renal disease (ESRD) is radio cephalic and brachio cephalic arteriovenous fistula (AVF).In patients with failed previous AVF e or poorly visualized or impalpable cephalic veins, the basilic vein can be mobilized and superficialized to create an AVF with the brachial artery.Objective: The aim of this study is to report our experience at the Vascular Surgery Department/ Surgical Specialty Hospital in brachio-basilic (BB) vascular access for hemodialysis.Methods: From January 2006 to December 2009, 31 patients with ESRD whose cephalic veins were thrombosed or impalpable or had previous unsuccessful vascular access procedures were referred to the Vascular
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