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Patent Glazing

Patent glazing pertains to a large area of glazing set within long glazing bars.
It refers to a non-load bearing, drained and ventilated framing system, used predominantly in overhead glazing.   Patent Glazing is the term applied to a self-draining and ventilated system of dry glazing that does not rely necessarily for its water tightness upon external glazing seals. It consists essentially of a series of longitudinal supporting members (glazing bars), and an infilling of glass or other suitable materials. Patent glazing bars are attached to and supported upon suitable structural members provided by others.
Patent Glazing is a generic term derived from early patents taken out to protect concepts of glazing bars having a drainage facility with dry glazing techniques. These early methods advanced the former putty glazed wood or iron bar methods, which required frequent maintenance.  Developments with modern materials, most commonly extruded aluminium, retain the early patent glazing principles and are still the most widely used product in overhead glazing.
Being an unsealed system, patent glazing in an overhead situation provides natural ventilation in the roof area in turn helping in minimizing excessive high temperatures. When used on a large roof area in a tiered application, patent glazing provides an effective drainage facility across the roof area.
Patent glazing applications can be found extensively in shopping malls, atria, schools, retail outlets, industrial units and conservatories. Canopies and walkways are also an ever-increasing use for this popular method of glazing.
Why Choose Patent Glazing?
Designed and installed in accordance with BS5516, patent glazing offers a unique combination of benefits, such as:
Elegance              With slender sight lines.
Flexibility            In complex roofs with hips and valleys or vertical glazing.
Economy            Value for money in first build or refurbishment applications
with minimal maintenance requirements.
Safety                Conforming to BS5516, it achieves high
standards for public safety.
Durability            Patent glazing has a heritage, which demonstrates a proven
good service life.

Specifying Patent Glazing
Information on patent glazing, to assist specification writing can be found in the National Building Specification, NBS section H10. Companies that provide patent glazing can also offer a free service for providing job specific specification sheets upon request. It is advisable to contact technical department at the early design stages of a project in order to discuss your specific requirements for the patent glazing and to agree suitable interface details with the surrounding structure.
All supply and fix contracts include for the preparation of detailed AutoCAD drawings for the Architect’s approval. A job specific method statement, risk analysis, and COSHH data sheets, along with health and safety policy, environmental policy and cleaning and maintenance manual accompany all order confirmations. As-Built information is usually supplied at the completion of the project to comply with the Construction (Design and Management) regulations.

Patent Foramen Ovale

Patent foramen ovale is a persistent opening in the wall of the heart which did not close completely after birth (opening required before birth for transfer of oxygenated blood via the umbilical cord). This opening can cause a shunt of blood from right to left , but more often there is a movement of blood from the left side of the heart (high pressure) to the right side of the heart (low pressure).
Fetuses have a normal opening between the left and right atria (upper chambers) of the heart. If this opening fails to close naturally soon after the baby is born, the condition is called patent foramen ovale (PFO).  Patent foramen ovale is the persistence of a fetal opening between the left and right atria (upper chambers) of the heart. This hole allows blood to bypass the lungs, because they are not used until a baby is born. The foramen ovale normally closes soon after the infant is born.  The foramen ovale may remain open in as many as 1 out of 5 people. The cause is unknown and there are no known risk factors for developing a patent foramen ovale or PFO.
A patent foramen ovale represents an interatrial communication that is common in children. The presence of patent foramen ovale rarely has clinical significance in situations where no other congenital heart defect is present.
People with shunts are less likely to develop fainting or low blood pressure with diving than are obstructive valve lesions (such as mitral valve stenosis or aortic stenosis), but are more likely to develop fluid accumulation in the lungs from heart failure and severe shortness of breath from the effects of combined exercise and water immersion. Ordinarily, the left to right shunt will cause no problem; the right to left shunt, if large enough, will cause low arterial O2 tension (hypoxia) and severely limited exercise capacity. In divers there is the risk of paradoxical embolism of gas bubbles (passage of bubbles into the arterial circulation) which occur in just about all divers in the venous circulation during decompression.
Several echocardiography and postmortem studies indicate that the foramen remains competent in 30% of patent foramen ovale patients with otherwise normal cardiac anatomy.
Mortality/Morbidity:
* The vast majority of patients with patent foramen ovale experience no symptoms throughout life.
* Morbidity, though rare, is predominantly due to paradoxical embolism. Cerebrovascular ischemic events can be attributed to paradoxical embolism through patent foramen ovale. This occurs more frequently in adults who experience deep-vein thrombosis or a hypercoagulable state. Risk of paradoxical air embolism is high in children and adults who undergo neurosurgical procedures. In particular, the sitting position for neurosurgery carries high risk for paradoxical air embolisms. Additionally, patients with pulmonary disease and high pulmonary vascular resistance are at risk for right-to-left shunting and paradoxical embolism.