Effect of latent heat release on mountain waves in a sheared mean flow

ABSTRACT. The effect of latent heat release on windward side of the mountain due to precipitation over the mountain waves has been studied assuming wind speed changing with respect to height. A single profile based on actual Peshawar data has been considered for the analysis. A thin level of heating has been chosen at medium level for the purpose of study. For non-hydrostatic case it is observed that in non-precipitation case when balanced heating/cooling takes place on the windward/leeward side or the mountain the effect of heating is negligibly small. However, for precipitation case downward displacement on the windward side, just above the level of heating. is obvious. Interference with the upstream current by the waves, produced due to elevated thermal forcing and reflected from the around surface is attributed to this phenomenon. Increase in the wave amplitude on the lee-side of the mountain as compared to non-precipitating case is also found. It is also revealed that higher the level or heating lesser the amplitude of the induced disturbance. 4.5 km agl is the level which is maximum affected by heating in general. For large and shallow mountainous terrains. hydrostatic solutions have been produced for three different levels of heating for sheared flow, Streamlines have been drawn. On comparison with no shear case, it may be inferred that shear effect is opposite to that due to thermal forcing.

A four-dimensional survey of the Almeria-Oran front by underwater gliders: Tracers and circulation

A four-dimensional survey by a fleet of 7 underwater gliders was used to identify pathways of subduction at the Almeria-Oran front in the western Mediterranean Sea. The combined glider fleet covered nearly 9000 km over ground while doing over 2500 dives to as deep as 700 m. The gliders had sensors to measure temperature, salinity, velocity, chlorophyll fluorescence and acoustic backscatter. Data from the gliders were analyzed through objective maps that were functions of across-front distance, along-front distance, and time on vertical levels separated by 10 m. Geostrophic velocity was inferred using a variational approach, and the quasigeostrophic omega equation was solved for vertical and ageostrophic horizontal velocities. Peak downward vertical velocities were near 25 m day-1 in an event that propagated in the direction of the frontal jet. An examination of an isopycnal surface that outcropped as the front formed showed consistency between the movement of the tracers and the inferred vertical velocity. The vertical velocity tended to be downward on the dense side of the front and upward on the light side so as to flatten the front in the manner of a baroclinic instability. The resulting heat flux approached 80 W m-2 near 100 m depth with a structure that would cause restratification of the front. One glider was used to track an isotherm over a day for a direct measure of vertical velocity as large as 50 m day-1, with a net downward displacement of 15 m over the day.

The impact of aerobic pretreatment of agro and industrial wastes on their biomethanation potential in Nisargruna technology

Anaerobic digestion is among the essential biological techniques used for stabilization of organic sludge from sewage and highly concentrated efflu-ents from food processing industries. It also recycles the municipal solid wastes into compost with simultaneous production of methane. The current study was performed to estimate the biomethanation potential of various agro- and industrial wastes like Jatropha de-oil cake, prawn shells, chicken feathers, bagasse, rice straw and wheat husk by mimicking the conditions in the biphasic Nisargruna biogas plant. A small volume of samples was chemi-cally characterized and allowed to decompose under aerobic and anaerobic conditions to determine the effect of aerobic predigestion (i.e. phase 1 of Nisargruna plant) on final methane production. The biogas produced was quantified by downward displacement of water. The observations indicated that approximately 60-80% methane was produced when Jatropha de-oil cake, prawn shells and rice straw was used. Conversely, the wheat straw and sugarcane wastes showed less methane formation, which may be due to the presence of complex polymers like lignocellulose and silica that considerably reduces the metabolic potential of microorganisms.

Investigating the vertical displacement of Duhok embankment Dam: A 31- Years Case Study

The paper studies the long-term settlement behaviour of more than 30-year of the Duhok dam. The dam uses as the major lake for water supply to the city of Duhok and nearby areas. High-precision levelling was used to measure the deformation of the dam to monitor vertical displacements. Five survey campaigns were conducted over 30-year duration: 1988, March 1990, June 1999, March 2017 and February 2019. Analysis of the results found that the highest downward displacement of roughly 20.4 cm was witnessed between 1988 and 2019 for a monitoring point (BM24) located centrally along the bank of the dam. On the other hand, the highest vertical movement of roughly 1.5 cm was estimated between 1990 and 2019 at the monitoring point (BM27) on the west side of the dam. The monitoring point (BM24) had the highest average absolute movement of about 6.0 mm (per year) over the 31 years. Detailed results and analyzes are presented in this article.

Ebstein Anomaly Focusing on Pre-excited Atrial Fibrillation Management

Introduction: Ebstein’s anomaly is a rare abnormality of the heart associated with atrialization right ventricle and apical (downward) displacement of the tricuspid valve functional annulus. Twenty percents of patients with Ebstein’s anomaly accompanied with accessory pathway. The dilatation of atrium and aging process may develop atrial fibrillation (AF).Case Description: A 35 years old patient with recurrency palpitation, accompanied with dizziness and epigastric discomfort. He had history of taking propafenone 3 x 150 mg for long time while the palpitation recurrent. He was hospitalization due to propafenone could not suppress the palpitation. During monitor in hospital revealed haemodynamic stable with heart rate 160-180 beats/minute irregularly irregular. The electrocardiography showed atrial fibrillation with pre-excitation WPW syndrome. We performed electrical cardioversion 100 joule. Then the atrial fibrillation was convert to sinus rhythm with WPW pattern. The propafenone 3 x 150mg was continued. The patient was performed catheter radiofrequency ablation of the accessory pathway. Electrophysiology showed AV fusion at right anteroseptal pathway and preexcited atrial fibrillation with shortest RR interval 220 ms that converted by cardioversion. The ablation was successfully performed. Discussion: The accessory pathway is a complication of ebstein anomaly. Digoxin, beta-blockers, diltiazem, verapamil, and amiodarone are potentially harmful in pre-excited atrial fibrillation. Propafenone reduces fast inward potential by sodium channels, reduces spontaneous automaticity and prolongs the effective refractory periode so could be used in this case. Catheter ablation of accessory pathway in Ebstein anomaly with WPW syndrome was class I recommendation. In our case, the accessory pathway was successfully ablated.

Arnold-Chiari Malformation: Core Concepts

Arnold-Chiari malformation (ACM), a defect that involves downward displacement of the hindbrain and herniation of the cerebellar vermis, tonsils, pons, medulla, and fourth ventricle through the foramen magnum, is the most complex of the 4 types of Chiari malformations. Unique to the other types of Chiari malformations, approximately 95 percent of infants with ACM also present with an associated myelomeningocele (MMC), the most severe form of spina bifida. Among affected infants, those with symptomatic comorbidities incur a significantly higher morbidity and mortality risk. Prompt identification and diagnosis of ACM, as well as evidence-based postnatal and postsurgical nursing and medical care, is critical. Early surgical intervention can repair an existing MMC and restore proper cerebrospinal fluid circulation, which can dramatically improve patient outcomes and quality of life, and reduce disease and health care burden.

Research on The Frame of Reference with The Downward Displacement of The Posterior Leaflet and Anterior Leaflet of Tricuspid Valve in Children by Ultrasound

To investigate the frame of reference with the downward displacement of the posterior leaflet and anterior leaflet of tricuspid valve in children by ultrasound.The downward degree of anterior and posterior tricuspid valve was evaluated with tricuspid annulus and coronary sinus as reference structures under ultrasound, and the position of tricuspid regurgitation orifice was shown by color ultrasound. Color Doppler flow imaging showed that the position of tricuspid regurgitation orifice moved down obviously in all 42 children. One case showed 2.2cm from the root of the anterior valve to the tricuspid annulus in the two-chamber and four-chamber view of the apical right heart. Color Doppler can show that the position and direction of tricuspid regurgitation orifice are obviously deviated to the anterolateral side. The obvious deviation of the tricuspid regurgitation orifice to the anterolateral direction may be an ultrasonic sign for diagnosing the downward displacement of the anterior tricuspid valve in children.

Unusual and nondescript type of distal clavicular fracture

Displaced fracture of the distal third of the clavicle usually occurs after direct trauma to the shoulder and typically results in superior displacement of the proximal fragment. We report a previously undescribed case of downward displacement of the clavicle caused by a fall on an outstretched hand, and we suggest the mechanism of injury.

Giant chondrosarcoma of the falx in an adolescent: A case report

Background: Intracranial chondrosarcomas are slowly growing malignant cartilaginous tumors that are especially rare in adolescents. Case Description: A 19-year-old woman with no medical history presented with symptoms of intermittent facial twitching and progressive generalized weakness for 6 months. The patient’s physical examination was unremarkable. Imaging revealed a large bifrontal mass arising from the falx cerebri, with significant compression of both cerebral hemispheres and downward displacement of the corpus callosum. The patient underwent a bifrontal craniotomy for gross total resection of tumor. Neuropathologic examination revealed a bland cartilaginous lesion most consistent with low-grade chondrosarcoma. Her postoperative course was uneventful, and she was discharged to home on postoperative day 3. Conclusion: This is an unusual case of an extra-axial, non-skull base, low-grade chondrosarcoma presenting as facial spasm in an adolescent patient.

Juvenile ossifying fibroma of the orbit: a rare location

<p class="abstract">Osseous tumors in the craniofacial skeleton of young patients are not very frequent, and tumors involving the walls of the orbital cavity are even more infrequent. Despite being usually slow-growing, even small neoformations can have a local aggressive behavior, displacing and compressing vital structures, and so it is important to perform an early diagnosis in order to avoid the tumor to pose problems on the optic nerve and threaten vision. The case that we are presenting shows an ossifying fibroma in a 19-year-old male from Ethiopia, a benign lesion whose progressive growth caused proptosis and downward displacement of the left eye. Following an adequate radiological diagnosis, we were able to delimit the fibroma existence and location. The surgery was conducted in a conservative form, allowing the patient not to suffer from post-surgery malformations. Histopathological diagnosis was compatible with juvenile ossifying fibroma, psammomatoid variant, arising from an uncommon location – the roof of the orbit. </p>