Portable Cylinders Research Articles

Repeated falling-head method for in situ measurements of saturated hydraulic conductivity using a single cylinder

A simple, repeated falling-head (RFH) method, which uses an inexpensive portable cylinder to quickly determine field-saturated hydraulic conductivity (Kfs), is presented. A cylinder of radius r, inserted vertically from the soil surface to a depth d, is used as a water supply tank, through which water infiltrates into the soil. The falling-head test is repeated without allowing the cylinder to be drained entirely to eliminate the effects of the initial soil moisture conditions. Either change in the water level (H) in the water supply cylinder or strong linearity between the infiltration flux (qs) and H can be used to determine Kfs directly or by multiplying the slope with an empirical ring-installation scaling length, Lg; thus, no soil-dependent variable is necessary. To obtain the Lg value for various conditions, we carried out numerical experiments using HYDRUS (2D/3D) with a recently implemented reservoir boundary condition for six different soil textures, ranging from coarse soil (e.g., sand) to fine soil (e.g., silty clay loam), and two different ranges of water levels, 15 ≤ H ≤ 25 cm and 2 ≤ H ≤ 6 cm. Numerical results showed that the Lg has a strong linear dependence on d and r, where Lg increases as d and r increase. We propose a new linear model to determine Lg with optimized coefficients for each H range. Numerical results showed no significant differences in the estimated Kfs after the second repetition, confirming that repeating the falling head test twice is sufficient. The newly obtained Lg values were then applied to the experimental data obtained at multiple fields having different soil textures. The Kfs values determined using the RFH method agreed well with those measured using the field two-ponding depths steady-state method and/or the FH method in the lab. These results demonstrate the reliability of the proposed RFH method.

Realising the transition to bioenergy: Integrating entrepreneurial business models into the biogas socio-technical system in Uganda

This study assesses the entrepreneurial potential and feasibility of developing a mobile system for purifying and bottling biogas in portable cylinders for wider society consumption and benefit. Our findings reveal that existing research has neglected the entrepreneurial potential in biogas energy that could increase energy supply and access in developing countries. Therefore, using a multimethod approach, the paper provides a comprehensive analysis of how an entrepreneurial business model could be developed and integrated into the biogas socio-technical system in Uganda. The analysis from the transitional model canvas shows that current biogas users have a relatively high satisfaction rate (50%) and with the adoption of the entrepreneurial business model this satisfaction could be captured on a wider social spectrum. Results from the feasibility study indicate that by sourcing materials locally, system builders (entrepreneurs) achieve a marginal cost reduction of 64% compared to when they are imported. Both findings from the transitional model canvas and the feasibility study indicate a high probability of not only reducing the supply gap but also a reliable energy source for developing countries and a potential for income generation and employment for the wider society.

Medical gas pipeline system as a limiting factor for hospital oxygen supply during COVID-19 outbreak.

Medical gas pipeline system as a limiting factor for hospital oxygen supply during COVID-19 outbreak.

Cylindrical Central Baffle Flume for Flow Measurements in Open Channels

AbstractThis work experimentally investigated a modified venturi flume formed by placing portable cylinders vertically upright in trapezoidal channels, referred to herein as the cylindrical central...

Strengthening Cervical Cancer Screening Program in Low Resource–Setting Communities: IPPF Success in Employing the Single-Visit Approach

Background and context: Cervical cancer is the 2nd most common cancer among women (WHO, 2012). It is estimated that 260,000 women die every year (WHO, 2014). Cervical cancer is preventable and can be treated if detected early, yet, it remains one of the leading causes of cancer-related deaths in the world. Nearly, 90% deaths occur in developing countries (WHO, 2014), and majority of women who suffer cervical cancer in sub-Saharan Africa seek care when the disease has advanced and is beyond the capacity of surgery or other treatment modalities. It is against this background that IPPF Member Associations in Kenya, Nigeria, Tanzania and Uganda, with other reproductive health network implemented the Cervical Cancer Screening and Preventive Therapy (CCS&PT) initiative. In the first 2 years, most women needing cryotherapy were lost to treatment due to referrals made. Aim: The initiative was to institutionalize and scale up the services, using visual inspection with acetic acid (VIA) & cryotherapy, through existing reproductive health networks to reach more people especially, the marginalized and vulnerable people. Strategy/Tactics: Main intervention used was the single visit approach facilitated by • Equipping all sites with cryo-machines to enable cryotherapy services • Providing portable cylinders (5-10 kg) to ensure adherence to SVA during outreaches. • Capacity building of service providers in cryotherapy and continuous supportive supervision • Quality counseling prior to the VIA to ensure clients understood the importance of immediate treatment • Well planned logistics during outreaches to ensure a wider coverage and cryotherapy treatment. • Training of community health workers and mobilizers to ensure right information dissemination. • Use of media and collaboration with political and religious leaders helped local partners to raise awareness of cervical cancer. Program/Policy process: Used SVA at all screening sites to address the loss of clients needing cryotherapy and avert the progress to cancer disease stage. Outcomes: The game changer was the implementation of the single visit approach. Results recorded were; year 3- (59%), year 4- (94%), year 5- (92%) and year 6- (97%). What was learned: It is imperative to implement SVA with high degree of planning, organizing and coordination from the beginning of a project • Ensure resources and capacities to implement VIA and cryotherapy are in place by conducting a facility assessment • Ensure continuous training and mentorship to enhance providers competences. • Portable gas cylinders are very essential and convenient to ensure adherence to the practice of SVA. Conclusion: The single visit approach used strengthened the cervical cancer screening program, made treatment more accessible to a wider number of marginalized women. Thousands (514,681) were screened and 14,083 treated to avert progress to cancer stage in future, and this contributed to reduce cervical cancer related morbidity and mortality.

The microbial colonization profile of respiratory devices and the significance of the role of disinfection: a blinded study.

Approximately 10-40% of all the nosocomial infections are pulmonary, which lead to grave complications. Elderly, debilitated, or critically ill patients are at a high risk. The respiratory care equipments which include ventilators, humidifiers, nebulizers may have been identified as the potential vehicles which cause major nosocomial infections if they are colonized by fungi or bacteria. To determine the rate of colonization by bacteria and fungi of the oxygen humidifier chambers of the portable cylinders and central lines at our hospital. The Hudson's chambers of nebulizers were also studied for the same. Swab samples were obtained from the equipments by using sterile cotton swabs on a tuesday, as these chambers were usually cleaned on every Saturday. Spot samples were taken from the ICUs, wards, the casualty and OPDs on a single day. Air samples were also obtained on the same day to determine whether the fungal spore load in the inhaled room air was normal or high. We performed a disinfection with 70% ethanol after cleaning these devices. 53/70 (75.71%) samples showed fungal growth; out of which, 23/33 (69.70%) were from the ICU, 24/30(80%) were from the wards and 6/7 (85.71%) were from the OPDs. 23/30 (76.66%) swabs from the central line humidifiers, 18/23(78.26%) swabs from the O2 cylinder humidifiers and 8/17 (47.5%) swabs from the nebulizers grew bacteria. Of the total 61(87.14%) bacterial isolates, 42(68.85%) were gram negative bacteria and 19(31.14%) were gram positive cocci. Out of the 42 gram negative bacteria, 17 were multi-drug resistant like ESBL producers ie. Pseudomonas spp. (6) Acinetobacter spp.(4), Klebseilla pneumoniae (4), E.coli (2) and Stenotrophomonas maltophila (1). Our findings (before disinfection) showed that the colonization rate for fungi was 75% and that for bacteria, it was 87%. After the 70% ethanol disinfection and strict compliance with the hand hygiene, the colonization rates reduced significantly. The fungal colonization rate was reduced and only 15% fungi grew after the disinfection, while only 12% bacterial colonization rate was found. This study indicates a potential in-hospital source of allergens and infections. The oxygen and nebulizer chambers need to be cleaned more frequently with disinfectants, to control the possible nosocomial infections.

Ambulatory oxygen improves the effectiveness of pulmonary rehabilitation in selected patients with chronic obstructive pulmonary disease

The effect of ambulatory oxygen use during pulmonary rehabilitation (PR) has not yet been clearly established, but many studies have shown benefit from oxygen acutely. Two small studies to date demonstrated no clear benefit when oxygen was used in patients who desaturated on exertion during a PR programme. One study showed the benefit of using oxygen during PR in patients who were normoxic at rest and desaturated to a minimum of 88% on exertion. We conducted a single-blind, randomised controlled trial comparing PR undertaken either with or without ambulatory oxygen, in those with demonstrable benefit from oxygen at baseline. Subjects from three PR services were recruited who, during baseline assessment, desaturated by more than 4% and to less than 90% on exertion, and walked 10% or more further with ambulatory oxygen on endurance shuttle walk test. Patients were randomised to either room air or oxygen via portable cylinder, titrated to optimise pulse oxygen saturation but up to a maximum flow rate of 6 L/min. All patients then completed a twice weekly, 6- to 7-week PR programme. Data were analysed as per protocol. Totally 51 patients completed the study. At the end of PR, both groups improved with PR, with patients in the oxygen group demonstrating a highly statistically significantly greater mean improvement in endurance walking distance than the controls, 490 m (95% confidence interval 228-750; p ≤ 0.001), as well as clinically, although not statistically, significant changes in quality of life. The use of ambulatory oxygen during a 6- to 7-week PR programme greatly improved endurance walking distance in patients who desaturated on exertion with a positive acute response to ambulatory oxygen at baseline.

Oxygen delivery failure from faulty portable cylinder

Oxygen delivery failure from faulty portable cylinder

Outcomes of adult domiciliary oxygen therapy in pulmonary diseases

Domiciliary oxygen therapy has been used during the last five decades to alleviate hypoxemia and its consequences. It is considered to be one of the most expensive therapeutic methods currently available, but it is also the only therapeutic approach that can prolong survival in patients with chronic hypoxemia. Domiciliary oxygen therapy is also aimed at relieving dyspnea and improving exercise capacity and sleep quality. Portable cylinders, concentrators and portable liquid systems are the main delivery systems currently available and oxygen-conserving devices attached are aimed at improving their effectiveness. In order to minimize the associated costs, appropriate patient selection and reassessment are required. Domiciliary oxygen therapy is mostly prescribed in chronic obstructive pulmonary disease – a disease caused predominantly by smoking and in which airway obstruction results in reduced arterial oxygenation (hypoxemia). Domiciliary oxygen therapy effectiveness is best evaluated and documented in chronic obstructive pulmonary disease, which also accounts for most of its prescriptions. Therefore, this review focuses predominantly on this disease-related oxygen therapy.

Fleet configuration subject to stochastic demand: an application in the distribution of liquefied petroleum gas

We study the problem of configuring a fleet, in which vehicles receive information on-line about the demand that they should fulfil while they are on the road. In each district it must be decided the number of vehicles and their capacity. The objective function is to minimise the operational cost subject to constraints for the minimum delivery capacity, the maximum vehicle size and the average waiting time for customers. The last constraint is modelled as a queuing system that is adjusted according to the simulation of the delivery process of a Chilean company that distributes liquefied petroleum gas in portable cylinders. We provide the analytical form of all the components of the model, so it can be solved using a standard non-linear programming package. We show that the fleet may increase its sales by 3% and reduce the waiting time of customers 10% by allowing a set of vehicles to share the buffer of orders rather than having vehicles to exclusively serve smaller sectors.

New mosquito traps using carbon dioxide and heat

New mosquito traps were devised : electroshock and adhesive traps using carbon dioxide and heat for attracting and killing mosquitoes. The electroshock trap is supplied with carbon dioxide by a portable cylinder and with heat and high voltage by electric power. The adhesive trap is supplied with carbon dioxide by dry ice and with heat by heating chemical (hand warmer). Outdoor experiments were carried out in August and September in a shrine of Kitakyushu City, Japan and in February in the outskirts of Bangkok City, Thailand. A total of 899 mosquitoes were collected with 2 or 3 adhesive traps in 4 nights in Kitakyushu (maximum of 213,minimum of 24 and average of 89.9 mosquitoes per trap-night), and Aedes albopictus accounted for 99% of the captured mosquitoes. As many as 5,408 mosquitoes were captured with 3 adhesive traps in 4 nights in Bangkok (maximum of 1,003,minimum of 114 and average of 450.7 mosquitoes per trap-night), and most (99%) of the captured mosquitoes were identified as Culex quinquefasciatus. A total of 8,133 mosquitoes were captured with 2 electroshock traps in 4 nights in Bangkok (maximum of 1,519,minimum of 1,031 and average of 1,293.8 mosquitoes per trap-night).

Extreme Hazard: Correct ID Important for Chlorine

This article describes the diamond‐shaped warning signs required for storing or using hazardous chemicals. Their shape, size, color and lettering/numbering are explained, based on National Fire Protection Association (NFPA) No. 704, Standard System for the Identification of the Hazards of Materials. Also, NFPA No. 55, Standard for the Storage, Use, and Handling of Compressed and Liquefied Gases in Portable Cylinders, 1998 edition, is sited for labeling requirements. A list of resources is given for emergency advice and help when working with chlorine, and nine safety practices from AWWA Manual M3 are listed for the handling and storage of chlorine.

Prescription and usage of long-term oxygen therapy in patients with chronic obstructive pulmonary disease in the Netherlands

Long-term oxygen therapy (LTOT) has been shown to improve survival in hypoxaemic patients with chronic obstructive pulmonary disease (COPD). This has resulted in recommending the prescription of oxygen for at least 15 h day −1 in most European countries. In order to examine the prescription and usage of LTOT and to assess the adherence to international recommendations for its prescription, a survey was set up in a random sample of clients of the largest oxygen company in the Netherlands. After patients had been visited for an interview, additional postal surveys were sent to the physician who had prescribed LTOT and to the oxygen company. For 175 COPD patients the mean oxygen prescription and mean oxygen usage were 15·6 ± 5·8 and 14·1 ± 6·8 h day −1, respectively. In 62 patients (35%) oxygen was prescribed <15 h day −1, more often by non-chest physicians than by chest physicians ( P<0·0001), and 91 patients (52%) used oxygen <15 h day −1. Of 113 patients with a prescription ≥15 h day −1, 39 (35%) used oxygen <15 h day −1 and 74 for ≥15 h day −1. The latter were prescribed oxygen for more h day −1, had been longer on LTOT, had a higher resting flow rate, were prescribed a concentrator, employed portable cylinders and used oxygen in public significantly more often than the former. We conclude that in a selected group of LTOT patients with COPD both oxygen prescription and usage were often inadequate, particularly if LTOT was prescribed by non-chest physicians.

Technical Basis for Flawed Cylinder Test Specification to Assure Adequate Fracture Resistance of ISO High-Strength Steel Cylinder

High-pressure industrial gases (such as oxygen, nitrogen, argon, hydrogen, etc.) are stored and transported in portable cylinders. ISO TC58 SC3 has developed a draft specification 9809 for design and fabrication of high-pressure cylinders with maximum tensile strength limitation of 1100 N/mm2. In order to extend the ISO 9809 rules for higher than 1100 N/mm2 strength level cylinders, a working group WG14 was formed in 1989 to develop new rules to assure adequate fracture resistance. In 1994, WG14 recommended a simple, but unique flawed cylinder test method for design qualification of the cylinder and acceptance criteria to assure adequate fracture resistance. WG14 also recommended Charpy-V-notch impact tests to control the required fracture resistance on production cylinders. This paper presents the technical basis that was employed in developing the flawed cylinder test method and acceptance criteria. The specification was developed for seamless steel cylinders having actual strength in the range of 1100 to 1400 N/mm2 and cylindrical section wall thickness in the range of 3 to 10 mm. Flawed cylinder tests were conducted on several hundred cylinders of varying sizes and strength levels. The specification requires to demonstrate LEAK-BEFORE-BREAK performance of the cylinder having flaw length equal to 1.6 (o.d. × tdesign)0.5 at failure pressure = (tdesign/tactual) × Design Pressure.

Portable oxygen therapy: assessment and usage

Fifty portable oxygen assessments, based on 6-min walking tests, were reviewed to produce guidelines for assessment and prescription of portable oxygen, and to evaluate factors predicting benefit. Patients with a portable cylinder were questioned about benefits/difficulties and usage of portable oxygen. A significant improvement on the oxygen compared to the air walk was found (median 9.7%) which correlated with the oxygen desaturation on the baseline walk (r = 0.51, P less than 0.05). A placebo effect was demonstrated using an air cylinder (median improvement 6.1%). There was no correlation between improvement in walking distance and decrease in visual analogue scale (VAS) score of breathlessness. We recommend standard portable oxygen assessments based on a series of 6-min walks. Improvements of 10% in walking distance or VAS score from the oxygen to the air walk would lead to the patient being offered a portable oxygen cylinder.

Supplemental oxygen and exercise ability in chronic obstructive airways disease.

The influence of supplemental oxygen on exercise performance was assessed in 17 patients with severe airflow obstruction. Exercise capacity was measured by the six minute walking distance, by an endurance walking test, and by an endurance cycling test and comparison was made with performance when the patient was breathing air. In addition, the relation between the flow rate of supplemental oxygen and cycling endurance time was studied. Portable oxygen (41 min-1) carried by the patient increased the mean endurance walking time by 59% and the six minute walking distance by 17%. The endurance time for cycling at a constant work load was increased by 51% with oxygen at a flow rate of 21 min-1, by 88% at 41 min-1, and by 80% at 61 min-1. Supplemental oxygen prolonged the length of time that the patients were able to walk at a fixed speed. It also increased the mean speed achieved during a six minute walk but this was variable and did not occur in all the subjects. The benefit from supplemental oxygen was not cancelled by the effort of carrying the portable cylinder.

An oxygen conserving nasal cannula.

Oxygen administration via a nasal cannula incorporating a small collapsible reservoir (Oxymizer, Chad Therapeutics Inc, California) was compared with delivery via a standard nasal cannula. Twelve patients with chronic, stable hypoxaemia (arterial oxygen tension less than 60 mm Hg (8.0 kPa)) were studied. Transcutaneous oxygen and carbon dioxide tensions were recorded by skin electrodes and oxygen saturation by ear oximetry. Baseline measurements during the breathing of air were compared with those made during the breathing of oxygen at flow rates of 0.5, 1.0, and 2.0 l/min via each device. Increases in saturation and transcutaneous oxygen tension were significantly greater at each flow rate with the reservoir device than with the conventional cannula. To produce similar improvements in oxygenation the reservoir device required an oxygen flow rate about half that of the conventional cannula. Use of the reservoir device may reduce the inconvenience and perhaps the cost of supplying domiciliary oxygen, and prolong the time during which patients may rely on a portable cylinder.

Oxygen Therapy Equipment-Reply

To the Editor:— The development of safe transfilling equipment was stimulated by the increasing use of ambulatory and emergency oxygen therapy. In the device referred to in the article cited, the 75- and 150-liter cylinders are equipped with a check valve which closes after the cylinder is filled and the transfilling device is disconnected. Of special importance is the fact that the orifice past the check valve is 0.003 sq. in. in area. The small size of this outlet prevents a projectile effect on the portable cylinders if a break in the connection should occur. The capillary tubing between the small and large cylinders is 0.02 in. in diameter. It has been recommended that a diaphragm check valve also be inserted at the nut connection to the large cylinder, the purpose of which would be to automatically shut off the escape of oxygen should the flow exceed 15 liters per