External Obstruction Research Articles

The influence of exterior obstruction on the integrated evaluation of daylight utilization during initial design stage

This paper presents a concise parametric study to investigate the influence of external obstruction on the evaluation of daylight utilization during design stage. A generic building located in Hong Kong has been established with dimmable controlled lighting system and interior shade. Multiple simulations under different external obstruction patterns are conducted with simulation engine EnergyPlus. Metrics on daylight availability, together with energy performance of both lighting and air conditioning system are analyzed. The result indicates that the ground floor is the most vulnerable to the existence of exterior obstruction and building zones of different orientation are affected in different ways. Further analysis also shows the impact from obstruction is not necessarily negative for daylight utilization cases. An overall assessment of this impact requires an integrated evaluation including both lighting and air conditioning system. These all demonstrate the necessity of taking exterior obstruction into consideration during the design stage.

Pediatric Cardiac Arrest Due to Trauma

Survival from pediatric cardiac arrest due to trauma has been reported to be 0.0%–8.8%. Some argue that resuscitation efforts in the case of trauma-related cardiac arrests are futile. We describe a successful outcome in the case of a child who suffered cardiac arrest caused by external traumatic airway obstruction. Our case illustrates how to deal with pediatric traumatic cardiac arrests in an out-of-hospital environment. It also illustrates how good clinical treatment in these situations may be supported by correct treatment after hospital admission when it is impossible to ventilate the patient to provide sufficient oxygen delivery to vital organs. This case relates to a lifeless child of 3–5 years, blue, and trapped by an electrically operated garage door. The first ambulance arrived to find several men trying to bend the frame and the door apart in order to extricate the child, who was hanging in the air with head and neck squeezed between the horizontally-moving garage door and the vertical door frame. One paramedic found a car jack and used it to push the door and the frame apart, allowing the lifeless child to be extricated. Basic life support was then initiated. Intubation was performed by the anesthesiologist without drugs. With FiO2 1.0 the first documented SaO2 was <50%. Restoration of Spontaneous Circulation was achieved after thirty minutes, and she was transported to the hospital. After a few hours she was put on venous-arterial ECMO for 5.5 days and discharged home after two months. Outpatient examinations during the rest of 2013 were positive, and the child found not to be suffering from any injuries, either physical or mental. The last follow-up in October 2014 demonstrated she had made a 100% recovery and she started school in August 2014.

Preoperative external nasal compression: does it decrease emergence agitation after nasal surgery?

Background Emergence agitation after nasal surgeries in adults is common. Acute postoperative nasal obstruction with nasal packing is an important factor in developing agitation after nasal surgeries. Aim The aim of this study was to evaluate the effectiveness of preoperative nasal obstruction by means of external nasal compression on the incidence of emergence agitation after nasal surgeries. Methods Sixty patients of American Society of Anesthesiologists I or II between 20 and 45 years of age who were scheduled for nasal surgery were randomly assigned into three equal groups: the control (C) group, the T10 group, in which nasal compression was carried out for 10 min, and the T30 group, in which nasal compression was carried out for 30 min preoperatively. All patients received the same anesthetic technique. The incidence of agitation, and recovery characteristics were evaluated during emergence. Patient satisfaction was evaluated 24 h after surgery. Results There was a significantly lower incidence of emergence agitation and fentanyl consumption during the emergence period in the T30 group. Moreover, patient satisfaction with recovery was significantly higher in the T30 group. Conclusion Elective preoperative external nasal obstruction may decrease the incidence of emergence agitation and improve patient satisfaction with recovery after nasal surgery.

Intraoperative endoscopic treatment of Mirizzi syndrome in a pediatric patient

Abstract Mirizzi syndrome occurs when an impacted gallstone, together with an associated inflammatory response, causes external obstruction of the common hepatic duct or common bile duct. Patients classically present with obstructive jaundice, right upper quadrant pain, and sometimes with fever. Mirizzi syndrome is a rare presentation of complicated gallstone disease and is even more rare in the pediatric population. However, as the number of obese pediatric patients increases, so does the incidence of gallstone-related disease. We present a case of Mirizzi syndrome treated by open cholecystectomy and cystic duct stone extraction in a pediatric patient. Recognition and awareness of Mirizzi syndrome is important, even in the pediatric population, to aid in safe operative intervention and to avoid intraoperative bile duct injury.

A comprehensive sensitivity study of major passive design parameters for the public rental housing development in Hong Kong

This paper presents a comprehensive SA (sensitivity analysis) of the typical PRH (public rental housing) development in Hong Kong based on a combined building energy, daylight and AFN (airflow network) simulation. A generic building model is constructed with a proposed MM (mixed-mode) ventilation control strategy to fulfill the thermal comfort requirement in the local green building guidance. The numerical modeling results are used to conduct both local and global sensitivity analyses to determine the relative importance of major passive design parameters, which comprehensively cover design aspects of the building layout, envelop thermophysics, building geometry and infiltration & air-tightness. The calculated global and local sensitivity indices on the cooling energy prove that the window solar heat gain coefficient, window to ground ratio, external obstruction and overhang projection fraction are the four most influential passive design factors. Similar results are also obtained when the lighting energy is specified as the output of the sensitivity analysis. The optimized building model derived from the sensitivity analysis is anticipated to achieve an energy saving of 41.6% compared to the baseline model as stipulated by the local building regulation. It is believed that sensitivity analysis is useful for identifying crucial design parameters to facilitate further optimization of the building performance in early architectural design stages.

Long-term Monitoring and Simulations of the Daylighting and Thermal Performance of an Anidolic Daylighting System on a Tropical Urban House

A poorly lit interior due to high external obstruction from the neighbourhood is a common problem in dense urban settlements. To improve the daylighting performance; meanwhile, to maintain its thermal performance of a living room in a tropical urban house, an anidolic daylighting system (ADS) was applied on the east facade. Long-term monitoring and simulations were conducted before and after the ADS installation to assess the room's daylighting and thermal performance. The living room's daylight levels and the daylighting glare probability (DGP) were analyzed using Radiance and Evalglare based lighting simulation softwares. Design Builder was employed to observe the thermal impact of the application. Whereas, the long-term monitoring of the ADS performance covered field measurements of the living room's daylight levels, DGP, air temperature, relative humidity and ADS collector's surface temperature before and after the ADS installation. Long-term monitoring and simulation results prove that ADS is a promising solution for daylighting problems in tropical regions. It convincingly improved the daylight levels within the imperceptible glare range without the increasing of the indoor air temperature.

Daylighting Design for Energy Saving in a Building Global Energy Simulation Context

A study on the impact that different daylighting solutions have on the global energy demand of a space is presented. The methodology relies on dynamic simulations carried out with Daysim and EnergyPlus used in synergy to perform a parametric study to assess the indoor daylighting conditions and the energy performance of rooms with different architectural features: room depth, window size, external obstruction angle and glazing visible transmittance. Furthermore, different lighting and shading control strategies were tested. The results of the study demonstrated that optimizing daylight can lead to a reduction of up to 30% in the global energy demand for a building.

An east-facing anidolic daylighting system on a tropical urban house

Sustainable core daylighting is expected to provide comfortable and healthy daylight in dense urban areas. One system, an anidolic daylighting system is a promising solution, however, it is still not widespread because of several complications. This paper presents an application of an affordable anidolic daylighting system on a tropical urban house designed with a simple edge-ray approach. This approach has created a parabolic collector for east-facing (azimuth 85°) anidolic daylighting system to improve the daylighting level of a room with high external obstruction. Simulation results and short-term monitoring before and after the construction have indicated successful application of an anidolic daylighting system for improving daylighting performance, especially before 13:00, without increasing indoor air temperature. The results have shown a strong hourly illuminance profile. To improve the indoor illuminance after 13:00 and the hourly illuminance profile, an east-facing anidolic daylighting system collector can be combined with a west-facing collector.

The effects of daylighting and human behavior on luminous comfort in residential buildings: A questionnaire survey

A questionnaire survey was conducted to investigate the effects of daylighting and human behavior patterns on subjective luminous comfort in Hong Kong housing units. The participants were recruited via mail, and included residents of both public and private housing units. 340 questionnaires were returned and analyzed by using SPSS 19.0. In analyzing the response statistics, the Cronbach's alpha coefficient, Spearman rank correlation coefficient, Chi-square test, Kruskal–Wallis test and stepwise regression were adopted to identify the effects of particular aspects of human behavior and daylighting quality. The results confirmed that luminous comfort is a function of both behavior patterns and daylighting conditions. Behavior factors have a significant influence on luminous comfort among people who grade their satisfaction with daylighting as moderate. In general, the degree of luminous comfort is most affected by satisfaction with daylighting. External obstruction is the major physical factor affecting luminous comfort, while the perception of uniformity is the major factor of residents' feelings toward daylight. The use of artificial lighting is the most relevant behavior factor affecting luminous comfort, as using artificial lighting for many hours per day indicates poor daylighting conditions and decreased luminous comfort. These results should help to raise awareness of the detailed factors that influence the luminous environment. Our findings may also assist planners and architects to implement better daylighting for housing projects and provide residents with greater luminous comfort.

Assessment of daylight in rooms with different architectural features

Results are presented from a parametric study that assessed the amount of daylight in rooms with different architectural features: the orientation, window size and visible glazing transmittance, room depth, external obstruction angle and site. Annual lighting simulations were run in order to understand how the daylight availability within a space changes as a function of the architectural features. A sub-dataset of the full result database is examined in detail for north- and south-facing rooms in Turin, north-west Italy, with a visible glazing transmittance of 70%. Each feature is analysed for its influence on the daylighting conditions. A simple graphical tool is presented to promote an easier reading of the results. This was developed to provide a synthesis of information to the design team. It shows the influence of preliminary design solutions on the amount of indoor daylight. This allows a design team to assess indoor daylighting from the earliest design phases onwards and to determine which combinations of architectural features are able to provide high, acceptable or low daylight levels within a room.

Profitability Goals, Control Goals, and the R&amp;D Investment Decisions of Family and Nonfamily Firms

Research and development (R&amp;D) investments can help build sustainable competitive advantages and improve firm performance. Nevertheless, managers also acknowledge the difficulties associated with managing R&amp;D and the low chances of success of innovation programs. For this reason, researchers have long been interested in understanding how managers make R&amp;D investment decisions. Research grounded in the behavioral theory of the firm suggests that a primary driver of R&amp;D investment decisions is profitability: when profitability goals have not been met, managers are more likely to initiate a problemistic search through increasing R&amp;D investments. While emphasizing profitability goals and their relationship with R&amp;D investments, prior research largely downplays the role of goals beyond profitability that exist in a significant number of firms (family firms) that are owned and managed by family members whose primary concern is preserving their control over the organization. Research indicates that these family‐centered noneconomic goals lead family managers to minimize R&amp;D investments and that the coexistence of multiple goals produces highly variable R&amp;D investment behavior. Yet, how family‐centered goals for control and profitability enter decision‐making in family firms is not fully understood. In this study, we propose that family managers form distinctive reference points that capture supplier bargaining power and are used to evaluate the degree of external obstruction to their managerial control. The empirical analysis of panel data on 431 private Spanish manufacturing firms observed over the period 2000–2006 shows that the importance of profitability and control goals follows a sequential logic in family firms, such that family firms react more strongly to increasing supplier bargaining power when their profitability reference points have been reached. This study extends current understanding of the distinctive organizational processes engendered by family management in business organizations leading to new research opportunities at the intersection of the innovation management and family business literatures.

Juvenile Hyalin Fibromatosis as a Cause of External Nasal Obstruction

Juvenile Hyalin Fibromatosis as a Cause of External Nasal Obstruction

PI3K Mediates Stretch-Induced COX-2 Expression During Urinary Tract Obstruction

Stretch-induced cyclooxygenase-2 (COX-2) expression occurs in urothelial cells during urinary tract obstruction (UTO). This increases COX-2-dependent prostanoid synthesis in stretched urothelial cells. These prostanoids then act on afferent neurons and smooth muscle cells in the ureter to amplify nociceptive and contractile responses, respectively. We previously used a unilateral ureteral obstruction (UUO) mouse model and a primary human urothelial cell (HUC) stretch model to describe ureteral COX-2 expression during UTO. The current study was performed to determine whether phosphatidylinositol 3-kinase (PI3K)-dependent signaling pathways are necessary for stretch-induced COX-2 expression in urothelial cells. Adult male CD-1 mice were treated with 25% dimethyl sulfoxide/phosphate buffered saline or PI3K inhibitor LY294002 (3 mg/kg, 30 mg/kg) for 1 hour before performing UUO for up to 4 hours. Obstructed and contralateral mouse ureters were analyzed via immunohistochemistry or Western blotting to assess in vivo stretch-induced COX-2 expression. In addition, HUCs were cyclically stretched (5%-20% displacement, 12 cycles/min) on collagen I-coated stretch plates and assessed for COX-2 expression via Western blotting. Histologic analyses of obstructed ureters show that urothelial cells stretch in response to external obstruction, COX-2 expression increases in the stretched urothelial cells, and no infiltrating immune cells were present under the conditions of the study. PI3K inhibitor LY294002 (30 mg/kg) attenuated in vivo stretch-induced COX-2 expression. LY294002 or RNA-interference also attenuated (HUC) stretch-induced COX-2 expression in vitro. Furthermore, the results also show that LY294002 inhibits stretch-induced protein kinase C (PKCζ) activation previously identified upstream of stretch-induced COX-2 expression in HUCs. The results indicate that PI3K is a mediator of stretch-induced COX-2 expression in urothelial cells. Identifying molecules that couple urothelial cell stretch to COX-2 expression may provide targets of drug action for effective therapeutics for UTO.

Aesthetic rhinoplasty: Avoiding unfavourable results

Rhinoplasty is one of the most challenging surgical procedures in plastic surgery. It is not surprising that a significant number of patients end up with unfavourable outcomes. Many of these unfavourable outcomes could be the result of poor judgment and wrong decision making. Most frequently, the unfavourable outcome is the result of errors in surgical technique. In this paper, unfavourable outcomes resulting from errors in surgical technique are discussed under the heading of each operative step. Poor placement of intra-nasal incision can result in internal valve obstruction. Bad columellar scars can result from errors during open rhinoplasty. Unfavourable results associated with skeletonisation are mentioned. Tip plasty, being the most difficult part of rhinoplasty, can result in lack of tip projection, asymmetry and deformities associated with placement of tip grafts. Over-resection of the lower lateral cartilages during tip plasty can also result in pinched nose, alar collapse causing external valve obstruction and other alar rim deformities. Humpectomy can result in open roof deformity, inverted V deformity and over-resection resulting in saddle nose. The so-called poly beak deformity is also a preventable unfavourable outcome when dealing with a large dorsal hump. Complications resulting from osteotomies include narrowing of nasal airway, open roof deformity, inverted V deformity and asymmetry of the bony wall resulting from incomplete or green stick fractures. Judicious use of grafts can be very rewarding. By the same token, grafts also carry with them the risk of complications. Allografts can result in recurrent infection, atrophy of the overlying skin and extrusion resulting in crippling deformities. Autografts are recommended by the author. Unfavourable results from autografts include displacement of graft, visibility of the graft edges, asymmetry, warping, and resorption.

Hydrodynamic and dispersion behavior in a non-porous silica monolith through fluid dynamic study of a computational mimic reconstructed from sub-micro-tomographic scans

An analysis of the transport properties of the bulk homogeneous core of a commercially available silica monolith (Chromolith®) is presented via direct numerical simulations in a topological model reconstructed from 3D nanotomographic scans at isotropic resolutions of 390nm, 290nm and 190nm. The pore and skeleton size distributions were calculated from image analysis and a representative unit cell from each resolution was reconstructed to simulate the hydrodynamic transport properties using Computational Fluid Dynamics (CFD). A 30μm×30μm×30μm unit cell extracted at 190nm resolution was found to be representative of hydrodynamic permeability. Numerical peak parking simulations yielded an axial external obstruction factor (γe) of 0.8. Mass transfer characteristics of a large non-penetrating molecule (BSA) were evaluated under non-retained conditions so as to elucidate the eddy dispersion contribution to total HETP. Transverse and axial dispersion length scales in the reconstructed model were resolved and related to the structural heterogeneities in the silica monolith. Deviations of simulated HETP from experimental measurements were attributed to a transcolumn dispersion contribution, which amounted to about 90% of the total HETP. The presented approach provides great scope to analyze the contributions of pore network topology to separation performance of silica monoliths (and other porous media) in HPLC applications. A significant reduction in simulation time and memory resources has been observed due to the lower scanning resolution, without significant loss in prediction accuracy.

Mirizzi syndrome: History, current knowledge and proposal of a simplified classification

Chronic complications of symptomatic gallstone disease, such as Mirizzi syndrome, are rare in Western developed countries with an incidence of less than 1% a year. The importance and implications of this condition are related to their associated and potentially serious surgical complications such as bile duct injury, and to its modern management when encountered during laparoscopic cholecystectomy. The pathophysiological process leading to the subtypes of Mirizzi syndrome has been explained by means of a pressure ulcer caused by an impacted gallstone at the gallbladder infundibulum, leading to an inflammatory response causing first external obstruction of the bile duct, and eventually eroding into the bile duct and evolving to a cholecystocholedochal or cholecystohepatic fistula. This article reviews the life of Pablo Luis Mirizzi, describes the earlier and later descriptions of Mirizzi syndrome, discusses the pathophysiological process leading to the development of these uncommon fistulas, reviews the current diagnostic modalities and surgical approaches and finally proposes a simplified classification for Mirizzi syndrome intended to standardize the reports on this condition and to eventually develop a consensual surgical approach to this unexpected and seriously dangerous condition.

Performance of Anidolic Daylighting Systems in tropical climates – Parametric studies for identification of main influencing factors

Making daylight more available in buildings is highly desirable, not only for reasons of energy-efficiency, but also for improvement of occupants’ health and well-being. Core-daylighting, that is daylight provision in areas situated at considerable distances from façades and windows, is currently one of the main challenges in sustainable building design. Anidolic Daylighting Systems (ADSs) are one very promising technology in the field of core-daylighting, but commercial solutions that are not only well-performing but also financially competitive are not yet widely available. This article presents results of parametric studies on Anidolic Integrated Ceilings (AICs), a special type of ADS, for identification of main influencing factors. The article describes a reliable method for simulating ADS and AIC performance under given sky conditions. Various simulation results for the example location Singapore are discussed in detail, it is concluded that the main influencing factors are coating material, system dimensions and external obstruction, and those influencing factors’ potential impacts are quantified. It is shown that AIC overall efficiencies can reach up to almost 50% in Singapore. The essentially new results presented in this article can be of great help to architects, engineers and scientists in the future, when it comes to precisely dimensioning ADS for various buildings and daylight conditions.

Adam Smith: libertad individual y mercado

El punto de partida del concepto general de hombre en el mundo moderno se formó en el siglo XVII: el hombre como una parte de la naturaleza. Pero esto tiene un particular significado en cuanto a que sus orígenes están fundados en el concepto cristiano de hombre que desarrolló el pensamiento medieval. De acuerdo con esta perspectiva, el individuo está compuesto de alma y cuerpo, espíritu y materia, como sustancias diferentes. Mediante la voluntad de Dios alma y cuerpo están unidos y ambos componen al individuo. Esta perspectiva abre la posibilidad de analizar al individuo y su relación social bajo la m i sma perspectiva de la física. Ésta es la aproximación de Hobbes, quien en el contexto de la física política plantea la explicación de las relaciones entre el individuo y la sociedad. El individuo es una máquina compleja. Desde esta perspectiva es posible explicar sus movimientos en términos de pasiones y funcionan como partes de una compleja máquina. Para Hobbes, la libertad humana significa que este mecanismo puede funcionar sin ninguna obstrucción externa.

Rule of Thumb for Daylighting of Rooms with External Obstructions

A daylighting rule of thumb or simplified formula for side-lit room with external obstruction has been presented by Littlefair. Based on Littlefair's formula and daylighting simulations generated by AGi-32, a modified rule of thumb for daylighting is proposed for a location in Sydney, New South Wales (Latitude −35° South and Longitude −150° East). Previous daylighting rules of thumb for Sydney based upon simulations using Lumen Micro 8 are revisited and revised. Lumen Micro 8 has been noted for its tendency of giving higher illuminance readings compared to other simulation software. In this research, AGi-32 is utilized in daylighting simulation of medium to large size rooms with external obstructions angles ranging from 5° to 80° from the window sill height (or work plane). The impacts of different surface reflectances (0% and 25%) of external obstructions on indoor illuminance are also examined.

Hearing loss in Mozambique: Current data from Inhambane Province

Mozambique is a developing African country recuperating from a lengthy civil war. As a result, documenting the incidence of hearing loss has remained a low priority. This paper provides results from work being carried out by the Mozambique Audiology Program (MAP), which is a philanthropic effort established in 1997 to introduce audiology services and identify auditory disorders in the country. Some decades before the MAP, another program reported extremely high incidence rates of otitis media in 1000 primary school students in the capital city of Maputo. This paper presents the MAP results from mass hearing screenings conducted over a two year period on a cohort group of 2685 students ranging in age from 3–18 years at a preschool and primary school in Chicuque and Maxixe, Mozambique. This current study showed a prevalence of 5% of the total 2685 students across ages with varying degrees of hearing loss resulting from multiple etiologies. External auditory canal obstruction was the greatest otoscopic abnormality (regardless of age), followed by severely limited tympanic membrane mobility (i.e. flat tympanogram) in the absence of EAC obstruction in those students identified with hearing loss. Of the 145 student identified with hearing loss, there were 27 found to have active drainage. Some of the benefits of conducting mass hearing screening in this population are discussed.