Search results for: perforated sacs
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 78

Search results for: perforated sacs

18 Study on Technological Development for Reducing the Sulfur Dioxide Residue Problem in Fresh Longan for Exporting

Authors: Wittaya Apai, Satippong Rattanakam, Suttinee Likhittragulrung, Nuttanai Tungmunkongvorakul, Sompetch Jaroensuk

Abstract:

The objective of this study was to find some alternative ways to decrease sulfur dioxide (SO₂) residue problem and prolong storage life in fresh longan for export. Office of Agricultural Research and Development Region 1, Chiang Mai province conducted the research and development from 2016-2018. A grade longan cv. Daw fruit with panicle attached was placed in 11.5 kg commercial perforated plastic basket. They had 5 selected treatments comprising of 3 baskets as replication for each treatment, i.e. 1.5% SO₂ fumigation prior to insert SO₂-generated pads (Uvasys®) (1.5% SO₂+SO₂ pad), dipping in 5% hydrochloric acid (HCl) mixed with 1% sodium metabisulfite (SMS) for 5 min (5% HCl +1% SMS), ozone (O₃) fumigation for 1 hours (h) prior to 1.5% SO₂ fumigation (O₃ 1 h+1.5% SO₂), 1.5% SO₂ fumigation prior to O₃ fumigation for 1 h (1.5% SO₂+O₃ 1 h) and 1.5% SO₂ fumigation alone as commercial treatment (1.5% SO₂). They were stored at 5 ˚C, 90% relative humidity (RH) for 40-80 days. The results found that the possible treatments were 1.5% SO₂+O₃ 1 h and 5% HCl +1% SMS respectively and prevented pericarp browning for 80 days at 5 ºC. There were no significant changes in some parameters in any treatments; 1.5% SO₂+O₃ 1 h and 1.5% SO₂ during storage, i.e., pericarp browning, flesh discoloration, disease incidence (%) and sensory evaluation during storage. Application 1.5% SO₂+O₃ 1 h had a tendency less both SO₂ residue in fruit and disease incidence (%) including brighter pericarp color as compared with commercial 1.5% SO₂ alone. Moreover, HCl 5%+SMS 1% showed the least SO₂ residue in whole fruit below codex tolerance at 50 mg/kg throughout period of time. The fruit treated with 1.5% SO₂+O₃ 1 h, 1.5% SO₂, 5% HCl+1% SMS, O₃ 1 h+1.5% SO₂, and 1.5% SO₂+SO₂ pad could prolong storage life for 40, 40, 40, 30 and 30 days respectively at 5°C, 90% RH. Thus, application 1.5% SO₂+O₃ 1 h and/or 5% HCl +1% SMS could be used for extending shelf life fresh longan exported to restricted countries due to less SO₂ residue and fruit quality was maintained as compared with the conventional method.

Keywords: longan, sulfur dioxide, ozone fumigation, sodium metabisulfite

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17 Effects of Duct Geometry, Thickness and Types of Liners on Transmission Loss for Absorptive Silencers

Authors: M. Kashfi, K. Jahani

Abstract:

Sound attenuation in absorptive silencers has been analyzed in this paper. The structure of such devices is as follows. When the rigid duct of an expansion chamber has been lined by a packed absorptive material under a perforated membrane, incident sound waves will be dissipated by the absorptive liners. This kind of silencer, usually are applicable for medium to high frequency ranges. Several conditions for different absorptive materials, variety in their thicknesses, and different shapes of the expansion chambers have been studied in this paper. Also, graphs of sound attenuation have been compared between empty expansion chamber and duct of silencer with applying liner. Plane waves have been assumed in inlet and outlet regions of the silencer. Presented results that have been achieved by applying finite element method (FEM), have shown the dependence of the sound attenuation spectrum to flow resistivity and the thicknesses of the absorptive materials, and geometries of the cross section (configuration of the silencer). As flow resistivity and thickness of absorptive materials increase, sound attenuation improves. In this paper, diagrams of the transmission loss (TL) for absorptive silencers in five different cross sections (rectangle, circle, ellipse, square, and rounded rectangle as the main geometry) have been presented. Also, TL graphs for silencers using different absorptive material (glass wool, wood fiber, and kind of spongy materials) as liner with three different thicknesses of 5 mm, 15 mm, and 30 mm for glass wool liner have been exhibited. At first, the effect of substances of the absorptive materials with the specific flow resistivity and densities on the TL spectrum, then the effect of the thicknesses of the glass wool, and at last the efficacy of the shape of the cross section of the silencer have been investigated.

Keywords: transmission loss, absorptive material, flow resistivity, thickness, frequency

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16 The Side Effect of the Perforation Shape towards Behaviour Flexural in Castellated Beam

Authors: Harrys Purnama, Wardatul Jannah, Rizkia Nita Hawari

Abstract:

In the development of the times, there are many materials used to plan a building structure. Steel became one of the most widely used materials in building construction that works as the main structure. Steel Castellated Beam is a type of innovation in the use of steel in building construction. Steel Castellated Beam is a beam that used for long span construction (more than 10 meters). The Castellated Beam is two steel profiles that unified into one to get the appropriate profile height (more than 10 meters). The profile is perforated to minimize the profile's weight, increase the rate, save costs, and have architectural value. The perforations shape in the Castellated Beam can be circular, elliptical, hexagonal, and rectangular. The Castellated beam has a height (h) almost 50% higher than the initial profile thus increasing the axial bending value and the moment of inertia (Iₓ). In this analysis, there are 3 specimens were used with 12.1 meters span of Castellated Beam as the sample with varied perforation, such us round, hexagon, and octagon. Castellated Beam testing system is done with computer-based applications that named Staad Pro V8i. It is to provide a central load in the middle of the steel beam span. It aims to determine the effect of perforation on bending behavior on the steel Castellated Beam by applying some form of perforations on the steel Castellated Beam with test specimen WF 200.100.5.5.8. From the analysis, results found the behavior of steel Castellated Beam when receiving such central load. From the results of the analysis will be obtained the amount of load, shear, strain, and Δ (deflection). The result of analysis by using Staad Pro V8i shows that with the different form of perforations on the profile of Castellated steel, then we get the different tendency of inertia moment. From the analysis, results obtained the moment of the greatest inertia can increase the stiffness of Castellated steel. By increasing the stiffness of the steel Castellated Beam the deflection will be smaller, so it can withstand the moment and a large strength. The results of the analysis show that the most effective and efficient perforations are the steel beam with a hexagon perforation shape.

Keywords: Castellated Beam, the moment of inertia, stress, deflection, bending test

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15 Optimization of an Electro-Submersible Pump for Crude Oil Extraction Processes

Authors: Deisy Becerra, Nicolas Rios, Miguel Asuaje

Abstract:

The Electrical Submersible Pump (ESP) is one of the most artificial lifting methods used in the last years, which consists of a serial arrangement of centrifugal pumps. One of the main concerns when handling crude oil is the formation of O/W or W/O (oil/water or water/oil) emulsions inside the pump, due to the shear rate imparted and the presence of high molecular weight substances that act as natural surfactants. Therefore, it is important to perform an analysis of the flow patterns inside the pump to increase the percentage of oil recovered using the centrifugal force and the difference in density between the oil and the water to generate the separation of liquid phases. For this study, a Computational Fluid Dynamic (CFD) model was developed on STAR-CCM+ software based on 3D geometry of a Franklin Electric 4400 4' four-stage ESP. In this case, the modification of the last stage was carried out to improve the centrifugal effect inside the pump, and a perforated double tube was designed with three different holes configurations disposed at the outlet section, through which the cut water flows. The arrangement of holes used has different geometrical configurations such as circles, rectangles, and irregular shapes determined as grating around the tube. The two-phase flow was modeled using an Eulerian approach with the Volume of Fluid (VOF) method, which predicts the distribution and movement of larger interfaces in immiscible phases. Different water-oil compositions were evaluated, such as 70-30% v/v, 80-20% v/v and 90-10% v/v, respectively. Finally, greater recovery of oil was obtained. For the several compositions evaluated, the volumetric oil fraction was greater than 0.55 at the pump outlet. Similarly, it is possible to show an inversely proportional relationship between the Water/Oil rate (WOR) and the volumetric flow. The volumetric fractions evaluated, the oil flow increased approximately between 41%-10% for circular perforations and 49%-19% for rectangular shaped perforations, regarding the inlet flow. Besides, the elimination of the pump diffuser in the last stage of the pump reduced the head by approximately 20%.

Keywords: computational fluid dynamic, CFD, electrical submersible pump, ESP, two phase flow, volume of fluid, VOF, water/oil rate, WOR

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14 Effect of Gravity on the Controlled Cooling of a Steel Block by Impinging Water Jets

Authors: E.K.K. Agyeman, P. Mousseau, A. Sarda, D. Edelin

Abstract:

The uniform and controlled cooling of hot metals by the circulation of water in canals remains a challenge due to the phase change of the water and the high heat fluxes associated with the phase change. This is because, during the cooling process, the phases are not uniformly distributed along the canals with the liquid phase dominating at the entrances of the canals and the gaseous phase dominating towards the exits. The difference in thermal properties between both phases leads to a heterogeneous temperature distribution in the part being cooled. Slowing down the cooling process is also a challenge due to the high heat fluxes associated with the phase change of water. This study investigates the use of multiple water jets for the controlled and homogenous cooling of hot metal parts and the effect of gravity on the effectiveness of the cooling process with a potential application in the cooling of composite forming moulds. A hole is bored at the centre of a steel block along its length. The jets are generated from the holes of a perforated steel pipe which is placed along the centre of the hole bored in the steel block. The evolution of the temperature with respect to time on the external surface of the steel block is measured simultaneously by thermocouples and an infrared camera. Different jet positions are tested in order to identify the jet placement configuration that ensures the most homogenous cooling of the block while the cooling speed is controlled by an intermittent impingement of the jets. In order to study the effect of gravity on the cooling process, a scenario where the jets are oriented in the opposite direction to that of gravity is compared to one where the jets are aligned in the same direction as gravity. It’s observed that orienting the jets in the direction of gravity reduces the effectiveness of the cooling process on the face of the block facing the impinging jets. This is due to the formation of a deeper pool of water due to the effect gravity and of the curved surface of the canal. This deeper pool of water influences the boiling regime characterized by a slower bubble evacuation when compared to the scenario where the jets are opposed to gravity.

Keywords: cooling speed, gravity, homogenous cooling, jet impingement

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13 Fluid Prescribing Post Laparotomies

Authors: Gusa Hall, Barrie Keeler, Achal Khanna

Abstract:

Introduction: NICE guidelines have highlighted the consequences of IV fluid mismanagement. The main aim of this study was to audit fluid prescribing post laparotomies to identify if fluids were prescribed in accordance to NICE guidelines. Methodology: Retrospective database search of eight specific laparotomy procedures (colectomy right and left, Hartmann’s procedure, small bowel resection, perforated ulcer, abdominal perineal resection, anterior resection, pan proctocolectomy, subtotal colectomy) highlighted 29 laparotomies between April 2019 and May 2019. Two of 29 patients had secondary procedures during the same admission, n=27 (patients). Database case notes were reviewed for date of procedure, length of admission, fluid prescribed and amount, nasal gastric tube output, daily bloods results for electrolytes sodium and potassium and operational losses. Results: n=27 based on 27 identified patients between April 2019 – May 2019, 93% (25/27) received IV fluids, only 19% (5/27) received the correct IV fluids in accordance to NICE guidelines, 93% (25/27) who received IV fluids had the correct electrolytes levels (sodium & potassium), 100% (27/27) patients received blood tests (U&E’s) for correct electrolytes levels. 0% (0/27) no documentation on operational losses. IV fluids matched nasogastric tube output in 100% (3/3) of the number of patients that had a nasogastric tube in situ. Conclusion: A PubMed database literature review on barriers to safer IV prescribing highlighted educational interventions focused on prescriber knowledge rather than how to execute the prescribing task. This audit suggests IV fluids post laparotomies are not being prescribed consistently in accordance to NICE guidelines. Surgical management plans should be clearer on IV fluids and electrolytes requirements for the following 24 hours after the plan has been initiated. In addition, further teaching and training around IV prescribing is needed together with frequent surgical audits on IV fluid prescribing post-surgery to evaluate improvements.

Keywords: audit, IV Fluid prescribing, laparotomy, NICE guidelines

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12 Evaluation of Double Displacement Process via Gas Dumpflood from Multiple Gas Reservoirs

Authors: B. Rakjarit, S. Athichanagorn

Abstract:

Double displacement process is a method in which gas is injected at an updip well to displace the oil bypassed by waterflooding operation from downdip water injector. As gas injection is costly and a large amount of gas is needed, gas dump-flood from multiple gas reservoirs is an attractive alternative. The objective of this paper is to demonstrate the benefits of the novel approach of double displacement process via gas dump-flood from multiple gas reservoirs. A reservoir simulation model consisting of a dipping oil reservoir and several underlying layered gas reservoirs was constructed in order to investigate the performance of the proposed method. Initially, water was injected via the downdip well to displace oil towards the producer located updip. When the water cut at the producer became high, the updip well was shut in and perforated in the gas zones in order to dump gas into the oil reservoir. At this point, the downdip well was open for production. In order to optimize oil recovery, oil production and water injection rates and perforation strategy on the gas reservoirs were investigated for different numbers of gas reservoirs having various depths and thicknesses. Gas dump-flood from multiple gas reservoirs can help increase the oil recovery after implementation of waterflooding upto 10%. Although the amount of additional oil recovery is slightly lower than the one obtained in conventional double displacement process, the proposed process requires a small completion cost of the gas zones and no operating cost while the conventional method incurs high capital investment in gas compression facility and high-pressure gas pipeline and additional operating cost. From the simulation study, oil recovery can be optimized by producing oil at a suitable rate and perforating the gas zones with the right strategy which depends on depths, thicknesses and number of the gas reservoirs. Conventional double displacement process has been studied and successfully implemented in many fields around the world. However, the method of dumping gas into the oil reservoir instead of injecting it from surface during the second displacement process has never been studied. The study of this novel approach will help a practicing engineer to understand the benefits of such method and can implement it with minimum cost.

Keywords: gas dump-flood, multi-gas layers, double displacement process, reservoir simulation

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11 Histogenesis of the Stomach of Pre-Hatching Quail: A Light and Electron Microscopic Study

Authors: Soha A Soliman, Yasser A Ahmed, Mohamed A Khalaf

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Although the enormous literature describing the histology of the stomach of different avian species during the posthatching development, the available literature on the pre-hatching development of quail stomach development is scanty. Thus, the current study was undertaken to provide a careful description of the main histological events during the embryonic development of quail stomach. To achieve this aim, daily histological specimens from the stomach of quail of 4 days post-incubation till the day 17 (few hours before hatching) were examined with light microscopy. The current study showed that the primitive gut tube of the embryonic quail appeared at the 4th day post incubation, and both parts of stomach (proventriculus and gizzard) were similar in structure and composed of endodermal epithelium of pseudostratified type surrounded by undifferentiated mesenchymal tissue. The sequences of the developmental events in the gut tube were preceded in a cranio-caudal pattern. By the 5th day, the endodermal covering of the primitive proventriculus gave rise to sac-like invaginations. The primitive gizzard was distinguished into thick-walled bodies and thin-walled sacs. In the 6th day, the prospective proventricular glandular epithelium became canalized and the muscular layer was developed in the cranial part of the proventriculus, whereas the primitive muscular coat of the gizzard was represented by a layer of condensed mesenchyme. In the 7th day, the proventricular glandular epithelial invaginations increased in depth and number, while, the muscularis mucosa and the muscular layer began to be distinguished. In the 8th day, the myoblasts differentiated into spindle shaped smooth muscle fibers. In the 10th day, branching of the proventricular glands began. The branching continued later on. The surface and the glandular epithelium were transformed into simple columnar type in the 12th day. The epithelial covering of the gizzard gave rise to tubular invaginations lined by simple cuboidal epithelium and the surface epithelium became simple columnar. Canalization of the tubular glands was recognized in the 14th day. In the 15th day, the proventricular surface epithelium invaginated in an concentric manner around a central cavity to form immature secretory units. The central cavity was lined by eosinophilic cells which form the ductal epithelia. The peripheral lamellae were lined by basophilic cells; the undifferentiated oxyntico-peptic cells. Entero-endocrine cells stained positive for silver impregnation in the proventricular glands. The mucosal folding in the gizzard appeared in the 15th day to form the plicae and the sulci. The wall of the proventriculus and gizzard in the 17th day acquired the main histological features of post-hatching birds, but neither the surface nor the ductal epithelium were differentiated to mucous producing cells. The current results shoed be considered in the molecular developmental studies.

Keywords: quail, proventriculus, gizzard, pre-hatching, histology

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10 Analysis of Genic Expression of Honey Bees Exposed to Sublethal Pesticides Doses Using the Transcriptome Technique

Authors: Ricardo de Oliveira Orsi, Aline Astolfi, Daniel Diego Mendes, Isabella Cristina de Castro Lippi, Jaine da Luz Scheffer, Yan Souza Lima, Juliana Lunardi, Giovanna do Padro Ribeiro, Samir Moura Kadri

Abstract:

NECTAR Brazilian group (Center of Education, Science, and Technology in Rational Beekeeping) conducted studies on the pesticides honey bees effects using the transcriptome sequencing (RNA-Seq) analyzes for gene expression studies. In this way, we analyzed the effects of Pyraclostrobin and Fipronil on the honey bees with 21 old-days (forager) in laboratory conditions. For this, frames containing sealed brood were removed from the beehives and maintenance on the stove (32°C and 75% humidity) until the bees were born. So, newly emerged workers were marked on the pronotum with a non-toxic pen and reintroduced into their original hives. After 21 days, 120 marked bees were collected with an entomological forces and immediately stored in Petri dishes, perforated to ensure ventilation, and kept fasted for 3 hours. These honeybees were exposed to food contaminated or not with the sublethal dose of Pyraclostrobin (850 ppb/bee) or Fipronil (2.5 ppb/bee). After four hours of exposure, 15 bees from each treatment were referred to transcriptome analysis. Total RNA analysis was extracted from the brain pools (03 brains per pool) using the TRIzol® reagent protocol according to the manufacturer's instructions. cDNA libraries were constructed, and the FASTQC program was used to check adapter content and assess the quality of raw reads. Differential expression analysis was performed with the DESeq2 package. Genes that had an adjusted value of less than 0.05 were considered to be significantly up-regulated. Regarding the Pyraclostrobin, alterations were observed in the pattern of 17 gene related to of antioxidant system, cellular respiration, glucose metabolism, and regulation of juvenile hormone and the hormone insulin. Glyphosate altered the 10 gene related to the digestive system, exoskeleton composition, vitamin E transport, and antioxidant system. The results indicate that the necessity of studies using the sublethal doses to evaluate the pesticides uses and risks on crops and its effects on the honey bees.

Keywords: beekeeping, honey bees, pesticides, transcriptome

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9 Shelf Life and Overall Quality of Pretreated and Modified Atmosphere Packaged ‘Ready-To-Eat’ Pomegranate arils cv. Bhagwa Stored at 1⁰C

Authors: Sangram Dhumal, Anil Karale

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The effect of different pretreatments and modified atmosphere packaging on the quality of minimally processed pomegranate arils of Bhagwa cultivar was evaluated during storage at 1⁰C for 16 days. Hand extracted pomegranate arils were pretreated with different antioxidants and surfactants viz., 100ppm sodium hypochlorite plus 0.5 percent ascorbic acid plus 0.5 percent citric acid, 10 and 20 percent honey solution, 0.1 percent nanosilver stipulated food grade hydrogen peroxide alone and in combination with 10 percent honey solution and control. The disinfected, rinsed and air-dried pomegranate arils were packed in polypropylene punnets (135g each) with different modified atmospheres and stored up to 16 days at 1⁰C. Changes in colour, pH, total soluble solids, sugars, anthocyanins, phenols, acidity, antioxidant activity, microbial and yeast and mold count over initial values were recorded in all the treatments under study but highest on those without antioxidant and surfactant treatments. Pretreated arils stored at 1⁰C recorded decrease in L*, b* value, pH, levels of non-reducing and total sugars, polyphenols, antioxidant activity and acceptability of arils and increase in total soluble solids, a* value, anthocyanins and microbial count. Increase in anthocyanin content was observed in modified atmosphere packaged pretreated arils stored at 1⁰C. Modified atmosphere packaging with 100 percent nitrogen recorded minimum changes in physicochemical and sensorial parameters with minimum microbial growth. Untreated arils in perforated punnets and with air (control) gave shelf life up to 6 days only. The pretreatment of arils with 10 percent honey plus 0.1 percent nanosilver stipulated food grade hydrogen peroxide and packaging in 100 percent nitrogen recorded minimum changes in physicochemical parameters. The treatment also restricted microbial growth and maintained colour, anthocyanin pigmentation, antioxidant activity and overall fresh like quality of arils. The same dipping treatment along with modified atmosphere packaging extended the shelf life of fresh ready to eat arils up to 14 to 16 days with enhanced acceptability when stored at 1⁰C.

Keywords: anthocyanin content, pomegranate, MAP, minimally processed, microbial quality, Bhagwa, shelf-life, overall quality

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8 Spontaneous Rupture of Splenic Artery Pseudoaneurysm; A Rare Presentation of Acute Abdominal Pain in the Emergency Department: Case Report

Authors: Zainab Elazab, Azhar Aziz

Abstract:

Background: Spontaneous Splenic artery pseudoaneurysm rupture is a rare condition which is potentially life threatening, if not detected and managed early. We report a case of abdominal pain with intraperitoneal free fluid, which turned out to be spontaneous rupture of a splenic artery pseudoaneurysm, and was treated with arterial embolization. Case presentation: A 28-year old, previously healthy male presented to the ED with a history of sudden onset upper abdominal pain and fainting attack. The patient denied any history of trauma or prior similar attacks. On examination, the patient had tachycardia and a low-normal BP (HR 110, BP 106/66) but his other vital signs were normal (Temp. 37.2, RR 18 and SpO2 100%). His abdomen was initially soft with mild tenderness in the upper region. Blood tests showed leukocytosis of 12.3 X109/L, Hb of 12.6 g/dl and lactic acid of 5.9 mmol/L. Ultrasound showed trace of free fluid in the perihepatic and perisplenic areas, and a splenic hypoechoic lesion. The patient remained stable; however, his abdomen became increasingly tender with guarding. We made a provisional diagnosis of a perforated viscus and the patient was started on IV fluids and IV antibiotics. An erect abdominal x-ray did not show any free air under the diaphragm so a CT abdomen was requested. Meanwhile, bedside ultrasound was repeated which showed increased amount of free fluid, suggesting intra-abdominal bleeding as the most probable etiology for the condition. His CT abdomen revealed a splenic injury with multiple lacerations, a focal intrasplenic enhancing area on venous phase scan (suggesting a pseudoaneurysm with associated splenic intraparenchymal, sub capsular and perisplenic hematomas). Free fluid in the subhepatic and intraperitoneal regions along the small bowel was also detected. Angiogram was done which confirmed a diagnosis of pseudoaneurysm of intrasplenic arterial branch, and angio-embolization was done to control the bleeding. The patient was later discharged in good condition with a surgery follow-up. Conclusion: Splenic artery pseudoaneurysm rupture is a rare cause of abdominal pain which should be considered in any case of abdominal pain with intraperitoneal bleeding. Early management is crucial as it carries a high mortality. Bedside ultrasound is a useful tool to help for early diagnosis of such cases.

Keywords: abdominal pain, pseudo aneurysm, rupture, splenic artery

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7 Uniform and Controlled Cooling of a Steel Block by Multiple Jet Impingement and Airflow

Authors: E. K. K. Agyeman, P. Mousseau, A. Sarda, D. Edelin

Abstract:

During the cooling of hot metals by the circulation of water in canals formed by boring holes in the metal, the rapid phase change of the water due to the high initial temperature of the metal leads to a non homogenous distribution of the phases within the canals. The liquid phase dominates towards the entrance of the canal while the gaseous phase dominates towards the exit. As a result of the different thermal properties of both phases, the metal is not uniformly cooled. This poses a problem during the cooling of moulds, where a uniform temperature distribution is needed in order to ensure the integrity of the part being formed. In this study, the simultaneous use of multiple water jets and an airflow for the uniform and controlled cooling of a steel block is investigated. A circular hole is bored at the centre of the steel block along its length and a perforated steel pipe is inserted along the central axis of the hole. Water jets that impact the internal surface of the steel block are generated from the perforations in the steel pipe when the water within it is put under pressure. These jets are oriented in the opposite direction to that of gravity. An intermittent airflow is imposed in the annular space between the steel pipe and the surface of hole bored in the steel block. The evolution of the temperature with respect to time of the external surface of the block is measured with the help of thermocouples and an infrared camera. Due to the high initial temperature of the steel block (350 °C), the water changes phase when it impacts the internal surface of the block. This leads to high heat fluxes. The strategy used to control the cooling speed of the block is the intermittent impingement of its internal surface by the jets. The intervals of impingement and of non impingement are varied in order to achieve the desired result. An airflow is used during the non impingement periods as an additional regulator of the cooling speed and to improve the temperature homogeneity of the impinged surface. After testing different jet positions, jet speeds and impingement intervals, it’s observed that the external surface of the steel block has a uniform temperature distribution along its length. However, the temperature distribution along its width isn’t uniform with the maximum temperature difference being between the centre of the block and its edge. Changing the positions of the jets has no significant effect on the temperature distribution on the external surface of the steel block. It’s also observed that reducing the jet impingement interval and increasing the non impingement interval slows down the cooling of the block and improves upon the temperature homogeneity of its external surface while increasing the duration of jet impingement speeds up the cooling process.

Keywords: cooling speed, homogenous cooling, jet impingement, phase change

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6 Effect of Laser Ablation OTR Films on the Storability of Endive and Pak Choi by Baby Vegetables in Modified Atmosphere Condition

Authors: In-Lee Choi, Min Jae Jeong, Jun Pill Baek, Ho-Min Kang

Abstract:

As the consumption trends of vegetables become different from the past, it is increased using vegetable more convenience such as fresh-cut vegetables, sprouts, baby vegetables rather than an existing hole piece of vegetables. Selected baby vegetables have various functional materials but they have short shelf life. This study was conducted to improve storability by using suitable laser ablation OTR (oxygen transmission rate) films. Baby vegetable of endive (Cichorium endivia L.) and pak choi (Brassica rapa chinensis) for this research, around 10 cm height, cultivated in glass greenhouse during 3 weeks. Harvested endive and pak choi were stored at 8 ℃ for 5 days and were packed by PP (Polypropylene) container and covered different types of laser ablation OTR film (DaeRyung Co., Ltd.) such as 1,300 cc, 10,000 cc, 20,000 cc, 40,000 cc /m2•day•atm, and control (perforated film) with heat sealing machine (SC200-IP, Kumkang, Korea). All the samples conducted 5 times replication. Statistical analysis was carried out using a Microsoft Excel 2010 program and results were expressed as standard deviations. The fresh weight loss rate of both baby vegetables were less than 0.3 % in treated films as maximum weight loss rate. On the other hands, control in the final storage day had around 3.0 % weight loss rate and it followed decreasing quantity. Endive had less 2.0 % carbon dioxide contents as maximum contents in 20,000 cc and 40,000 cc. Oxygen contents was maintained between 17 and 20 % in endive, 19 and 20 % in pak choi. Ethylene concentration of both vegetables maintained little lower contents in 20,000 cc treatments than others at final storage day without statistical significance. In the case of hardness, 40,000 cc film was shown little higher value at both baby vegetables without statistical significance. Visual quality was good at 10,000 cc and 20,000 cc in endive and pak choi, and off-flavor was not appeard any off-flavor in both vegetables. Chlorophyll (SPAD-502, Minolta, Japan) value of endive was shown as similar result with initial in all treatments except 20,000 cc as little lower. And chlorophyll value of pak choi decreased in all treatments compared with initial value but was not shown significantly difference each other. Color of leaves (CR-400, Minolta, Japan) changed significantly in 40,000 cc at endive. In an event of pak choi, all the treatments started yellowing by increasing hunter b value, among them control increased substantially. As above the result, 10,000 cc film was most reasonable packaging film for storing at endive and 20,000 cc at pak choi with good quality.

Keywords: carbon dioxide, shelf-life, visual quality, pak choi

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5 Assessing the Impact of Frailty in Elderly Patients Undergoing Emergency Laparotomies in Singapore

Authors: Zhao Jiashen, Serene Goh, Jerry Goo, Anthony Li, Lim Woan Wui, Paul Drakeford, Chen Qing Yan

Abstract:

Introduction: Emergency laparotomy (EL) is one of the most common surgeries done in Singapore to treat acute abdominal pathologies. A significant proportion of these surgeries are performed in the geriatric population (65 years and older), who tend to have the highest postoperative morbidity, mortality, and highest utilization of intensive care resources. Frailty, the state of vulnerability to adverse outcomes from an accumulation of physiological deficits, has been shown to be associated with poorer outcomes after surgery and remains a strong driver of healthcare utilization and costs. To date, there is little understanding of the impact it has on emergency laparotomy outcomes. The objective of this study is to examine the impact of frailty on postoperative morbidity, mortality, and length of stay after EL. Methods: A retrospective study was conducted in two tertiary centres in Singapore, Tan Tock Seng Hospital and Khoo Teck Puat Hospital the period from January to December 2019. Patients aged 65 years and above who underwent emergency laparotomy for intestinal obstruction, perforated viscus, bowel ischaemia, adhesiolysis, gastrointestinal bleed, or another suspected acute abdomen were included. Laparotomies performed for trauma, cholecystectomy, appendectomy, vascular surgery, and non-GI surgery were excluded. The Clinical Frailty Score (CFS) developed by the Canadian Study of Health and Aging (CSHA) was used. A score of 1 to 4 was defined as non-frail and 5 to 7 as frail. We compared the clinical outcomes of elderly patients in the frail and non-frail groups. Results: There were 233 elderly patients who underwent EL during the study period. Up to 26.2% of patients were frail. Patients who were frail (CFS 5-9) tend to be older, 79 ± 7 vs 79 ± 5 years of age, p <0.01. Gender distribution was equal in both groups. Indication for emergency laparotomies, time from diagnosis to surgery, and presence of consultant surgeons and anaesthetists in the operating theatre were comparable (p>0.05). Patients in the frail group were more likely to receive postoperative geriatric assessment than in the non-frail group, 49.2% vs. 27.9% (p<0.01). The postoperative complications were comparable (p>0.05). The length of stay in the critical care unit was longer for the frail patients, 2 (IQR 1-6.5) versus 1 (IQR 0-4) days, p<0.01. Frailty was found to be an independent predictor of 90-day mortality but not age, OR 2.9 (1.1-7.4), p=0.03. Conclusion: Up to one-fourth of the elderly who underwent EL were frail. Patients who were frail were associated with a longer length of stay in the critical care unit and a 90-day mortality rate of more than three times that of their non-frail counterparts. PPOSSUM was a better predictor of 90-day mortality in the non-frail group than in the frail group. As frailty scoring was a significant predictor of 90-day mortality, its integration into acute surgical units to facilitate shared decision-making and discharge planning should be considered.

Keywords: frailty elderly, emergency, laparotomy

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4 Analysis of Interparticle interactions in High Waxy-Heavy Clay Fine Sands for Sand Control Optimization

Authors: Gerald Gwamba

Abstract:

Formation and oil well sand production is one of the greatest and oldest concerns for the Oil and gas industry. The production of sand particles may vary from very small and limited amounts to far elevated levels which has the potential to block or plug the pore spaces near the perforated points to blocking production from surface facilities. Therefore, the timely and reliable investigation of conditions leading to the onset or quantifying sanding while producing is imperative. The challenges of sand production are even more elevated while producing in Waxy and Heavy wells with Clay Fine sands (WHFC). Existing research argues that both waxy and heavy hydrocarbons exhibit far differing characteristics with waxy more paraffinic while heavy crude oils exhibit more asphaltenic properties. Moreover, the combined effect of WHFC conditions presents more complexity in production as opposed to individual effects that could be attributed to a consolidation of a surmountable opposing force. However, research on a combined high WHFC system could depict a better representation of the surmountable effect which in essence is more comparable to field conditions where a one-sided view of either individual effects on sanding has been argued to some extent misrepresentative of actual field conditions since all factors act surmountably. In recognition of the limited customized research on sand production studies with the combined effect of WHFC however, our research seeks to apply the Design of Experiments (DOE) methodology based on latest literature to analyze the relationship between various interparticle factors in relation to selected sand control methods. Our research aims to unearth a better understanding of how the combined effect of interparticle factors including: strength, cementation, particle size and production rate among others could better assist in the design of an optimal sand control system for the WHFC well conditions. In this regard, we seek to answer the following research question: How does the combined effect of interparticle factors affect the optimization of sand control systems for WHFC wells? Results from experimental data collection will inform a better justification for a sand control design for WHFC. In doing so, we hope to contribute to earlier contrasts arguing that sand production could potentially enable well self-permeability enhancement caused by the establishment of new flow channels created by loosening and detachment of sand grains. We hope that our research will contribute to future sand control designs capable of adapting to flexible production adjustments in controlled sand management. This paper presents results which are part of an ongoing research towards the authors' PhD project in the optimization of sand control systems for WHFC wells.

Keywords: waxy-heavy oils, clay-fine sands, sand control optimization, interparticle factors, design of experiments

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3 Nonconventional Method for Separation of Rosmarinic Acid: Synergic Extraction

Authors: Lenuta Kloetzer, Alexandra C. Blaga, Dan Cascaval, Alexandra Tucaliuc, Anca I. Galaction

Abstract:

Rosmarinic acid, an ester of caffeic acid and 3-(3,4-dihydroxyphenyl) lactic acid, is considered a valuable compound for the pharmaceutical and cosmetic industries due to its antimicrobial, antioxidant, antiviral, anti-allergic, and anti-inflammatory effects. It can be obtained by extraction from vegetable or animal materials, by chemical synthesis and biosynthesis. Indifferent of the method used for rosmarinic acid production, the separation and purification process implies high amount of raw materials and laborious stages leading to high cost for and limitations of the separation technology. This study focused on separation of rosmarinic acid by synergic reactive extraction with a mixture of two extractants, one acidic (acid di-(2ethylhexyl) phosphoric acid, D2EHPA) and one with basic character (Amberlite LA-2). The studies were performed in experimental equipment consisting of an extraction column where the phases’ mixing was made by mean of a perforated disk with 45 mm diameter and 20% free section, maintained at the initial contact interface between the aqueous and organic phases. The vibrations had a frequency of 50 s⁻¹ and 5 mm amplitude. The extraction was carried out in two solvents with different dielectric constants (n-heptane and dichloromethane) in which the extractants mixture of varying concentration was dissolved. The pH-value of initial aqueous solution was varied between 1 and 7. The efficiency of the studied extraction systems was quantified by distribution and synergic coefficients. For calculating these parameters, the rosmarinic acid concentration in the initial aqueous solution and in the raffinate have been measured by HPLC. The influences of extractants concentrations and solvent polarity on the efficiency of rosmarinic acid separation by synergic extraction with a mixture of Amberlite LA-2 and D2EHPA have been analyzed. In the reactive extraction system with a constant concentration of Amberlite LA-2 in the organic phase, the increase of D2EHPA concentration leads to decrease of the synergic coefficient. This is because the increase of D2EHPA concentration prevents the formation of amine adducts and, consequently, affects the hydrophobicity of the interfacial complex with rosmarinic acid. For these reasons, the diminution of synergic coefficient is more important for dichloromethane. By maintaining a constant value of D2EHPA concentration and increasing the concentration of Amberlite LA-2, the synergic coefficient could become higher than 1, its highest values being reached for n-heptane. Depending on the solvent polarity and D2EHPA amount in the solvent phase, the synergic effect is observed for Amberlite LA-2 concentrations over 20 g/l dissolved in n-heptane. Thus, by increasing the concentration of D2EHPA from 5 to 40 g/l, the minimum concentration value of Amberlite LA-2 corresponding to synergism increases from 20 to 40 g/l for the solvent with lower polarity, namely, n-heptane, while there is no synergic effect recorded for dichloromethane. By analysing the influences of the main factors (organic phase polarity, extractant concentration in the mixture) on the efficiency of synergic extraction of rosmarinic acid, the most important synergic effect was found to correspond to the extractants mixture containing 5 g/l D2EHPA and 40 g/l Amberlite LA-2 dissolved in n-heptane.

Keywords: Amberlite LA-2, di(2-ethylhexyl) phosphoric acid, rosmarinic acid, synergic effect

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2 Combined Pneumomediastinum and Pneumothorax Due to Hyperemesis Gravidarum

Authors: Fayez Hanna, Viet Tran

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A 20 years old lady- primigravida 6 weeks pregnant with unremarkable past history, presented to the emergency department at the Royal Hobart Hospital, Tasmania, Australia, with hyperemesis gravidarum associated with, dehydration and complicated with hematemesis and chest pain resistant. Accordingly, we conducted laboratory investigations which revealed: FBC: WBC 23.9, unremarkable U&E, LFT, lipase and her VBG showed a pH 7.4, pCo2 36.7, cK+ 3.2, cNa+ 142. The decision was made to do a chest X-ray (CXR) after explaining the risks/benefit of performing radiographic investigations during pregnancy and considering the patient's plan for the termination of the pregnancy as she was not ready for motherhood for shared decision-making and consent to look for pneumoperitoneum to suggest perforated viscus that might cause the hematemesis. However, the CXR showed pneumomediastinum but no evidence of pneumoperitoneum or pneumothorax. Consequently, a decision was made to proceed with CT oesophagography with imaging pre and post oral contrast administration to identify a potential oesophageal tear since it could not be excluded using a plain film of the CXR. The CT oesophagography could not find a leak for the administered oral contrast and thus, no oesophageal tear could be confirmed but could not exclude the Mallory-Weiss tear (lower oesophageal tear). Further, the CT oesophagography showed an extensive pneumomediastinum that could not be confirmed to be pulmonary in origin noting the presence of bilateral pulmonary interstitial emphysema and pneumothorax in the apex of the right lung that was small. The patient was admitted to the Emergency Department Inpatient Unit for monitoring, supportive therapy, and symptomatic management. Her hyperemesis was well controlled with ondansetron 8mg IV, metoclopramide 10mg IV, doxylamine 25mg PO, pyridoxine 25mg PO, esomeprazole 40mg IV and oxycodone 5mg PO was given for pain control and 2 litter of IV fluid. The patient was stabilized after 24 hours and discharged home on ondansetron 8mg every 8 hours whereas the patient had a plan for medical termination of pregnancy. Three weeks later, the patient represented with nausea and vomiting complicated by a frank hematemesis. Her observation chart showed HR 117- other vital signs were normal. Pathology showed WBC 14.3 with normal U&E and Hb. The patient was managed in the Emergency Department with the same previous regimen and was discharged home on same previous regimes. Five days later, she presented again with nausea, vomiting and hematemesis and was admitted under obstetrics and gynaecology for stabilization then discharged home with a plan for surgical termination of pregnancy after 3-days rather than the previously planned medical termination of pregnancy to avoid extension of potential oesophageal tear. The surgical termination and follow up period were uneventful. The case is considered rare as pneumomediastinum is a very rare complication of hyperemesis gravidarum where vomiting-induced barotrauma leads to a ruptured oesophagus and air leak into the mediastinum. However no rupture oesophagus in our case. Although the combination of pneumothorax and pneumomediastinum without oesophageal tear was reported only 8 times in the literature, but none of them was due to hyperemesis gravidarum.

Keywords: Pneumothorax, pneumomediastinum, hyperemesis gravidarum, pneumopericardium

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1 Active Filtration of Phosphorus in Ca-Rich Hydrated Oil Shale Ash Filters: The Effect of Organic Loading and Form of Precipitated Phosphatic Material

Authors: Päärn Paiste, Margit Kõiv, Riho Mõtlep, Kalle Kirsimäe

Abstract:

For small-scale wastewater management, the treatment wetlands (TWs) as a low cost alternative to conventional treatment facilities, can be used. However, P removal capacity of TW systems is usually problematic. P removal in TWs is mainly dependent on the physico–chemical and hydrological properties of the filter material. Highest P removal efficiency has been shown trough Ca-phosphate precipitation (i.e. active filtration) in Ca-rich alkaline filter materials, e.g. industrial by-products like hydrated oil shale ash (HOSA), metallurgical slags. In this contribution we report preliminary results of a full-scale TW system using HOSA material for P removal for a municipal wastewater at Nõo site, Estonia. The main goals of this ongoing project are to evaluate: a) the long-term P removal efficiency of HOSA using real waste water; b) the effect of high organic loading rate; c) variable P-loading effects on the P removal mechanism (adsorption/direct precipitation); and d) the form and composition of phosphate precipitates. Onsite full-scale experiment with two concurrent filter systems for treatment of municipal wastewater was established in September 2013. System’s pretreatment steps include septic tank (2 m2) and vertical down-flow LECA filters (3 m2 each), followed by horizontal subsurface HOSA filters (effective volume 8 m3 each). Overall organic and hydraulic loading rates of both systems are the same. However, the first system is operated in a stable hydraulic loading regime and the second in variable loading regime that imitates the wastewater production in an average household. Piezometers for water and perforated sample containers for filter material sampling were incorporated inside the filter beds to allow for continuous in-situ monitoring. During the 18 months of operation the median removal efficiency (inflow to outflow) of both systems were over 99% for TP, 93% for COD and 57% for TN. However, we observed significant differences in the samples collected in different points inside the filter systems. In both systems, we observed development of preferred flow paths and zones with high and low loadings. The filters show formation and a gradual advance of a “dead” zone along the flow path (zone with saturated filter material characterized by ineffective removal rates), which develops more rapidly in the system working under variable loading regime. The formation of the “dead” zone is accompanied by the growth of organic substances on the filter material particles that evidently inhibit the P removal. Phase analysis of used filter materials using X-ray diffraction method reveals formation of minor amounts of amorphous Ca-phosphate precipitates. This finding is supported by ATR-FTIR and SEM-EDS measurements, which also reveal Ca-phosphate and authigenic carbonate precipitation. Our first experimental results demonstrate that organic pollution and loading regime significantly affect the performance of hydrated ash filters. The material analyses also show that P is incorporated into a carbonate substituted hydroxyapatite phase.

Keywords: active filtration, apatite, hydrated oil shale ash, organic pollution, phosphorus

Procedia PDF Downloads 251