Advances in mixed-matrix membranes for biorefining of biogas from anaerobic digestion.

This article provides a comprehensive review of the state-of-the-art technology of polymeric mixed-matrix membranes for CO/CH separation that can be applied in medium, small, and domestic biogas systems operating at low pressures (0.2-6 kPa). Critical data from the latest publications of CO/CH separation membranes were analyzed, considering the ratio of CO/CH permeabilities, the CO selectivity, the operating pressures at which the membranes were tested, the chemistry of the polymers studied and their gas separation mechanisms.

Lisfranc Arthrodesis in Posttraumatic Chronic Injuries.

Chronic injuries at the tarsometatarsal joint represent a wide array of painful malunions ranging from isolated instability to complex three-dimensional deformities with rapid development of posttraumatic arthritis. Deformity correction and arthrodesis of the symptomatic joints leads to significant pain reduction and functional improvement provided that realignment of the anatomic axes is achieved. Arthrodesis should be limited to the first to third tarsometatarsal joints, whereas interposition arthroplasty is preferred for symptomatic arthritis of the fourth to fifth tarsometatarsal joints.

Counting Salem Numbers of Arithmetic Hyperbolic 3-Orbifolds.

It is known that the lengths of closed geodesics of an arithmetic hyperbolic orbifold are related to Salem numbers. We initiate a quantitative study of this phenomenon. We show that any non-compact arithmetic 3-dimensional orbifold defines square-rootable Salem numbers of degree 4 which are less than or equal to .

Nutritional quality of wild Iberian red deer (Cervus elaphus hispanicus) meat: Effects of sex and hunting period.

The proximate composition, energetic value, minerals, B-group vitamins and pH value of the loin (longissimus thoracis) of 71 wild Iberian red deer (Cervus elaphus hispanicus), were evaluated in stags and hinds hunted in autumn and winter. In autumn, meat had a higher content of moisture, K, Na, Zn and thiamine when compared to winter, in which higher content of proteins and P were detected. Meat from stags had a higher moisture, Na, Zn and folic acid content, while hinds provided optimal pH values (<5.