**Chapter 15**

*Pain Management - Practices, Novel Therapies and Bioactives*

(ERAS) Society recommendations. World J Surg 2016; 40: 2065-2083.

M et al. Consensus review of optimal perioperative care in breast reconstruction: Enhanced Recovery After Surgery (ERAS) Society

2017; 139: 1056e–1071e

(Oxford) 2006; 45:765-770.

[36] Temple-Oberle C, Shea-Budgell MA, Tan M, Semple JL, Schrag C, Barreto

recommendations. Plast Reconstr Surg

[37] Shen H, et al: Analgesic action of acetaminophen in symptomatic osteoarthritis of the knee. Rheumatology

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**1.1 History of Nigeria**

Nigeria often referred to the giant of Africa is the largest Black nation in Africa. It is a country located in West Africa bordered by Cameroon in the East, Benin Republic in the West, Niger Republic to the North and Chad Republic to the North East. It is a federation consisting of 36 states with Abuja the Federal Capital territory as the capital. It is located on the Gulf of Guinea with a total area of 923,768 km2 (356,669 sq. miles). It is the world's 32nd-largest country. Nigeria got her independence from the British on 1st of October 1960. It has an estimated population of over 200 million people. The United Nations estimated the population in 2016 to be 185,989,640 distributed as 51.7% rural and 48.3% urban with a population density of 167.5 persons per square kilometre. Although the official language is English, there are more than 250 ethnic groups with well over 500 different native languages and diverse cultures. There are 3 major ethnic groups in Nigeria (Hausa/ Fulani, Igbo and Yoruba). Nigeria is a religiously diverse nation divided into a predominantly Christian South and Muslim North and a minority groups of traditional African religion. Nigeria is a mixed economy dependent and an emerging market. As at 2014 Nigeria was the fastest growing and largest economy in Africa. She is blessed with abundant natural resources and a developing communication, financial, legal and transportation sector. Nigeria is the 12th largest producer of oil in the world, the 8th largest exporter, has the 10th largest proven reserves and supplies a fifth of its oil to the United States of America. Oil plays a significant role in the Nigerian economy and accounts for 40% of GDP and 80% of all government earnings. Healthcare delivery is the responsibility of the 3 tiers of government (federal, state and local government). There is a number of health-related challenges in Nigeria (HIV/AIDS, malaria, polio, poor access to potable and clean water, lack of proper sanitation system, high infant and maternal mortality rates). Although the recurrent expenditure on health in Nigeria has increased over the years, healthcare delivery and infrastructural endowment remains suboptimal with health tourism on the increase [1]. The Nigerian health care system is continuously faced with a number of challenges; shortage of healthcare workers [2] predominantly due to significant emigration of skilled medical personnel to developed economies of the world (brain drain), suboptimal funding, decaying infrastructure, inter-professional conflict, perennial strike actions by healthcare professionals, lack of political will as well as bureaucratic bottlenecks in public health care delivery in Nigeria [3].


*Article* **Rheological Behavior of Spectrally Selective Coatings for Polymeric Solar Absorbers**

**Mohor Mihelˇciˇc 1, Marta Klanjšek Gunde 2 and Lidija Slemenik Perše 1,\***

**\*** Correspondence<EMAIL_ADDRESS>
**Abstract:** Since the world's energy demands are growing rapidly, there is a constant need for new energy systems. One of the cleanest, most abundant, and renewable natural resources available is solar energy; therefore, the development of surfaces with high absorption of solar radiation is increasing. To achieve the best efficiency, such surfaces are coated with spectrally selective coatings, which are strongly influenced by the pigments and resin binders. Spectrally selective paints have a very specific formulation, and since the applied dry coatings should exhibit high spectral selectivity, i.e., high solar absorptivity and low thermal emissivity, the rheological properties of liquid paints are of great importance. In the present work, we studied the effect of the rheological properties of liquid thickness-insensitive spectrally selective (TISS) paints on the spectral selectivity and adhesion of dry coatings on a polymeric substrate. The results showed that the functional and adhesion properties of dry coating on polymeric substrates is strongly dependent on the rheological properties of the binder and catalyst used for the preparation of the liquid paints. It was shown that the paints with good spectral selective properties (thermal emissivity *eT* < 0.36 and solar absorptivity *aS* > 0.92) and good adhesion (5B) can be prepared for polymer substrates.

**Keywords:** spectrally selective paints; polymer solar absorbers; rheological characterization